Номер 28, страница 14 - гдз по геометрии 10-11 класс учебник Атанасян, Бутузов

Геометрия, 10-11 класс Учебник, авторы: Атанасян Левон Сергеевич, Бутузов Валентин Фёдорович, Кадомцев Сергей Борисович, Позняк Эдуард Генрихович, Киселёва Людмила Сергеевна, издательство Просвещение, Москва, 2019, коричневого цвета

Авторы: Атанасян Л. С., Бутузов В. Ф., Кадомцев С. Б., Позняк Э. Г., Киселёва Л. С.

Тип: Учебник

Издательство: Просвещение

Год издания: 2019 - 2026

Уровень обучения: базовый и углублённый

Цвет обложки: коричневый с ромбами

ISBN: 978-5-09-103606-0 (2023)

Допущено Министерством просвещения Российской Федерации

Математика: алгебра и начала математического анализа, геометрия

Глава 1. Параллельность прямых и плоскостей. Параграф 1. Параллельность прямых, прямой и плоскости - номер 28, страница 14.

App\Models\Task {#1024 // resources/views/models/task/default.blade.php
  #connection: "mysql"
  #table: "tasks"
  #primaryKey: "id"
  #keyType: "int"
  +incrementing: true
  #with: []
  #withCount: []
  +preventsLazyLoading: false
  #perPage: 15
  +exists: true
  +wasRecentlyCreated: false
  #escapeWhenCastingToString: false
  #attributes: array:24 [
    "id" => 744443
    "created_at" => "2026-04-10 13:58:26"
    "updated_at" => null
    "field_page_start" => "14"
    "field_page_end" => null
    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/00-28"
    "field_display_title" => "28"
    "field_outside_task" => null
    "field_task_type" => Illuminate\Database\Eloquent\Collection {#331
      #items: array:1 [
        0 => App\Models\Term {#1029
          #connection: "mysql"
          #table: "terms"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: false
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 26
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "name" => "номер"
            "field_cases" => array:6 [
              "field_accusative_case" => "номер"
              "field_creative_case" => "номером"
              "field_dative_case" => "номеру"
              "field_genitive_case" => "номера"
              "field_nominative_case" => "номер"
              "field_prepositional_case" => "номере"
            ]
            "field_short_name" => ""
          ]
          #original: array:6 [
            "id" => 26
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "name" => "номер"
            "field_cases" => array:6 [
              "field_accusative_case" => "номер"
              "field_creative_case" => "номером"
              "field_dative_case" => "номеру"
              "field_genitive_case" => "номера"
              "field_nominative_case" => "номер"
              "field_prepositional_case" => "номере"
            ]
            "field_short_name" => ""
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "field_metatags_title" => null
    "field_metatags_description" => null
    "field_h1" => null
    "field_description_top" => null
    "field_description_bottom" => null
    "field_match" => null
    "breadcrumbs" => []
    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1026
      #items: []
      #escapeWhenCastingToString: false
    }
    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#342
      #items: array:1 [
        0 => App\Models\Branch {#1023
          #connection: "mysql"
          #table: "branches"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:24 [
            "id" => 744367
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Параллельность прямых и плоскостей"
            "field_branch_order" => "1"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#333
              #items: array:1 [
                0 => App\Models\Term {#1033
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #original: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "9"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1030
              #items: array:1 [
                0 => App\Models\Book {#1032
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 36
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1034 …2}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1036 …2}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1039 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1041 …2}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1047 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1048 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1050 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1052 …2}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1054 …2}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1055 …2}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1056 …2}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1058 …2}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1060 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1062 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
                    "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
                    "field_priority" => "12"
                    "field_default_folder" => "/geometrija_10/atanasjan-u23/"
                    "field_isbn" => "978-5-09-103606-0 (2023)"
                    "field_cover" => array:1 [ …1]
                    "field_cover_alts" => array:1 [ …1]
                    "field_covers" => array:1 [ …1]
                    "field_popular_book" => null
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1063 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1064 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1065 …2}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1066 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [ …3]
                  ]
                  #original: array:50 [
                    "id" => 36
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1034 …2}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1036 …2}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1039 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1041 …2}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1047 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1048 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1050 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1052 …2}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1054 …2}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1055 …2}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1056 …2}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1058 …2}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1060 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1062 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
                    "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
                    "field_priority" => "12"
                    "field_default_folder" => "/geometrija_10/atanasjan-u23/"
                    "field_isbn" => "978-5-09-103606-0 (2023)"
                    "field_cover" => array:1 [ …1]
                    "field_cover_alts" => array:1 [ …1]
                    "field_covers" => array:1 [ …1]
                    "field_popular_book" => null
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1063 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1064 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1065 …2}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1066 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [ …3]
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1068
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 744367
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Параллельность прямых и плоскостей"
            "field_branch_order" => "1"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#333}
            "field_page_start" => "9"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1030}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1068}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1069
      #items: array:2 [
        0 => App\Models\Branch {#1023}
        1 => App\Models\Branch {#1070
          #connection: "mysql"
          #table: "branches"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:24 [
            "id" => 744368
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Параллельность прямых, прямой и плоскости"
            "field_branch_order" => "1"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1071
              #items: array:1 [
                0 => App\Models\Term {#1072
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:7 [
                    "id" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #original: array:7 [
                    "id" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "9"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1073
              #items: array:1 [
                0 => App\Models\Book {#1074
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 36
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1075 …2}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1077 …2}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1080 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1082 …2}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1088 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1089 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1091 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1093 …2}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1095 …2}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1096 …2}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1097 …2}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1099 …2}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1101 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1103 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
                    "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
                    "field_priority" => "12"
                    "field_default_folder" => "/geometrija_10/atanasjan-u23/"
                    "field_isbn" => "978-5-09-103606-0 (2023)"
                    "field_cover" => array:1 [ …1]
                    "field_cover_alts" => array:1 [ …1]
                    "field_covers" => array:1 [ …1]
                    "field_popular_book" => null
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1104 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1105 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1106 …2}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1107 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [ …3]
                  ]
                  #original: array:50 [
                    "id" => 36
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1075 …2}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1077 …2}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1080 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1082 …2}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1088 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1089 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1091 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1093 …2}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1095 …2}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1096 …2}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1097 …2}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1099 …2}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1101 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1103 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
                    "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
                    "field_priority" => "12"
                    "field_default_folder" => "/geometrija_10/atanasjan-u23/"
                    "field_isbn" => "978-5-09-103606-0 (2023)"
                    "field_cover" => array:1 [ …1]
                    "field_cover_alts" => array:1 [ …1]
                    "field_covers" => array:1 [ …1]
                    "field_popular_book" => null
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1104 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1105 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1106 …2}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1107 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [ …3]
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1109
              #items: array:1 [
                0 => App\Models\Branch {#1110
                  #connection: "mysql"
                  #table: "branches"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [
                    "id" => 744367
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Параллельность прямых и плоскостей"
                    "field_branch_order" => "1"
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1111 …2}
                    "field_page_start" => "9"
                    "field_branch_display" => "0"
                    "field_branch_expanded" => "0"
                    "field_display_branch_in_title" => "1"
                    "field_display_task_interval" => "0"
                    "field_display_branch_page" => "1"
                    "field_branch_title_in_content" => "0"
                    "field_navigation_title" => null
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "field_branch_cover" => []
                    "field_branch_covers" => []
                    "book" => Illuminate\Database\Eloquent\Collection {#1113 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1114 …2}
                  ]
                  #original: array:24 [
                    "id" => 744367
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_display_title" => "Параллельность прямых и плоскостей"
                    "field_branch_order" => "1"
                    "field_url" => null
                    "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1111 …2}
                    "field_page_start" => "9"
                    "field_branch_display" => "0"
                    "field_branch_expanded" => "0"
                    "field_display_branch_in_title" => "1"
                    "field_display_task_interval" => "0"
                    "field_display_branch_page" => "1"
                    "field_branch_title_in_content" => "0"
                    "field_navigation_title" => null
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "field_branch_cover" => []
                    "field_branch_covers" => []
                    "book" => Illuminate\Database\Eloquent\Collection {#1113 …2}
                    "branch_parent" => Illuminate\Database\Eloquent\Collection {#1114 …2}
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 744368
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Параллельность прямых, прямой и плоскости"
            "field_branch_order" => "1"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1071}
            "field_page_start" => "9"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1073}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1109}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "content" => Illuminate\Database\Eloquent\Collection {#1115
      #items: array:6 [
        0 => App\Models\Element {#1116
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:7 [
            "id" => 938677
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1117
              #items: array:1 [
                0 => App\Models\Edition {#1118
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [
                    "id" => 2315
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Условие"
                    "field_order" => "1"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1119 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text, image"
                    "field_page_content_mode" => "image"
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "statement"
                    "field_root_dir" => "0-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1121 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1122 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1123 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 2315
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Условие"
                    "field_order" => "1"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1119 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text, image"
                    "field_page_content_mode" => "image"
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "statement"
                     …7
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "text" => "<p> <b>28.</b> На сторонах АВ и АС треугольника ABC взяты соответственно точки D и Е так, что длина отрезка DE равна 5 см и <span class="long"><span class="fraction"><span>BD</span><span>DA</span></span> = <span class="fraction"><span>2</span><span>3</span></span>.</span> Плоскость α проходит через точки В и С и параллельна отрезку DE. Найдите длину отрезка ВС. </p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.jpg"
                "alt" => null
                "width" => "1519"
                "height" => 297
                "path" => "/media/geometrija_10/atanasjan-u23/0-00/28-1.webp?ts=1739436312"
              ]
            ]
          ]
          #original: array:7 [
            "id" => 938677
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1117}
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "text" => "<p> <b>28.</b> На сторонах АВ и АС треугольника ABC взяты соответственно точки D и Е так, что длина отрезка DE равна 5 см и <span class="long"><span class="fraction"><span>BD</span><span>DA</span></span> = <span class="fraction"><span>2</span><span>3</span></span>.</span> Плоскость α проходит через точки В и С и параллельна отрезку DE. Найдите длину отрезка ВС. </p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.jpg"
                "alt" => null
                "width" => "1519"
                "height" => 297
                "path" => "/media/geometrija_10/atanasjan-u23/0-00/28-1.webp?ts=1739436312"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        1 => App\Models\Element {#1124
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 939575
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1125
              #items: array:1 [
                0 => App\Models\Edition {#1126
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [ …21]
                  #original: array:21 [ …21]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.png"
                "alt" => null
                "width" => "694"
                "height" => 3550
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/28-1.webp?ts=1739440860"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 939575
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1125}
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.png"
                "alt" => null
                "width" => "694"
                "height" => 3550
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/28-1.webp?ts=1739440860"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        2 => App\Models\Element {#1132
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 939399
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1133
              #items: array:1 [
                0 => App\Models\Edition {#1134
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [ …21]
                  #original: array:21 [ …21]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.jpg"
                "alt" => null
                "width" => "1325"
                "height" => 1184
                "path" => "/media/geometrija_10/atanasjan-u23/3-00/28-1.webp?ts=1739436488"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 939399
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1133}
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.jpg"
                "alt" => null
                "width" => "1325"
                "height" => 1184
                "path" => "/media/geometrija_10/atanasjan-u23/3-00/28-1.webp?ts=1739436488"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        3 => App\Models\Element {#1140
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 939696
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1141
              #items: array:1 [
                0 => App\Models\Edition {#1142
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [ …21]
                  #original: array:21 [ …21]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.jpg"
                "alt" => null
                "width" => "1210"
                "height" => 616
                "path" => "/media/geometrija_10/atanasjan-u23/4-00/28-1.webp?ts=1739436333"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 939696
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1141}
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.jpg"
                "alt" => null
                "width" => "1210"
                "height" => 616
                "path" => "/media/geometrija_10/atanasjan-u23/4-00/28-1.webp?ts=1739436333"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        4 => App\Models\Element {#1148
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 939827
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1149
              #items: array:1 [
                0 => App\Models\Edition {#1150
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [ …21]
                  #original: array:21 [ …21]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.jpg"
                "alt" => null
                "width" => "1329"
                "height" => 907
                "path" => "/media/geometrija_10/atanasjan-u23/5-00/28-1.webp?ts=1739436341"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 939827
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1149}
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "28-1.jpg"
                "alt" => null
                "width" => "1329"
                "height" => 907
                "path" => "/media/geometrija_10/atanasjan-u23/5-00/28-1.webp?ts=1739436341"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        5 => App\Models\Element {#1156
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 1351756
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1157
              #items: array:1 [
                0 => App\Models\Edition {#1158
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [ …21]
                  #original: array:21 [ …21]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "text" => "<p>По условию задачи, точки D и E лежат на сторонах AB и AC треугольника ABC соответственно. Плоскость $\alpha$ проходит через точки B и C, значит, прямая BC лежит в плоскости $\alpha$. Также дано, что плоскость $\alpha$ параллельна отрезку DE.</p><p>Рассмотрим плоскость, в которой лежит треугольник ABC. Эта плоскость содержит прямую DE. Согласно теореме о параллельности прямой и плоскости, если плоскость (в данном случае, плоскость $\triangle ABC$) проходит через прямую (DE), параллельную другой плоскости ($\alpha$), и пересекает эту плоскость, то линия пересечения этих плоскостей (прямая BC) параллельна данной прямой (DE).</p><p>Следовательно, мы можем утверждать, что отрезок $DE$ параллелен отрезку $BC$ ($DE \parallel BC$).</p><p>Теперь рассмотрим треугольники $\triangle ADE$ и $\triangle ABC$.</p><p>1. Угол $\angle A$ является общим для обоих треугольников.</p><p>2. Угол $\angle ADE$ равен углу $\angle ABC$ как соответственные углы при параллельных прямых $DE$ и $BC$ и секущей $AB$.</p><p>Таким образом, треугольник $\triangle ADE$ подобен треугольнику $\triangle ABC$ по двум углам.</p><p>Из подобия треугольников следует пропорциональность их сторон:</p><p>$\frac{AD}{AB} = \frac{AE}{AC} = \frac{DE}{BC}$</p><p>Коэффициент подобия $k = \frac{AB}{AD}$.</p><p>Из этой пропорции выразим искомую сторону $BC$:</p><p>$BC = DE \cdot \frac{AB}{AD}$</p><p>Найдем отношение $\frac{AB}{AD}$. Точка $D$ лежит на отрезке $AB$, поэтому $AB = AD + DB$.</p><p>По условию дано отношение $\frac{BD}{DA} = \frac{2}{3}$. Отсюда можно выразить $BD$ через $AD$:</p><p>$BD = \frac{2}{3} AD$</p><p>Подставим это в выражение для $AB$:</p><p>$AB = AD + \frac{2}{3} AD = (1 + \frac{2}{3}) AD = \frac{5}{3} AD$</p><p>Теперь найдем отношение $\frac{AB}{AD}$:</p><p>$\frac{AB}{AD} = \frac{\frac{5}{3} AD}{AD} = \frac{5}{3}$</p><p>Наконец, подставим все известные значения в формулу для $BC$. Нам дано, что $DE = 5$ см.</p><p>$BC = 5 \cdot \frac{5}{3} = \frac{25}{3}$ см.</p><p><strong>Ответ:</strong> $\frac{25}{3}$ см.</p>"
          ]
          #original: array:6 [
            "id" => 1351756
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1157}
            "task" => array:2 [
              "refs" => "744443"
              "type" => "task"
            ]
            "text" => "<p>По условию задачи, точки D и E лежат на сторонах AB и AC треугольника ABC соответственно. Плоскость $\alpha$ проходит через точки B и C, значит, прямая BC лежит в плоскости $\alpha$. Также дано, что плоскость $\alpha$ параллельна отрезку DE.</p><p>Рассмотрим плоскость, в которой лежит треугольник ABC. Эта плоскость содержит прямую DE. Согласно теореме о параллельности прямой и плоскости, если плоскость (в данном случае, плоскость $\triangle ABC$) проходит через прямую (DE), параллельную другой плоскости ($\alpha$), и пересекает эту плоскость, то линия пересечения этих плоскостей (прямая BC) параллельна данной прямой (DE).</p><p>Следовательно, мы можем утверждать, что отрезок $DE$ параллелен отрезку $BC$ ($DE \parallel BC$).</p><p>Теперь рассмотрим треугольники $\triangle ADE$ и $\triangle ABC$.</p><p>1. Угол $\angle A$ является общим для обоих треугольников.</p><p>2. Угол $\angle ADE$ равен углу $\angle ABC$ как соответственные углы при параллельных прямых $DE$ и $BC$ и секущей $AB$.</p><p>Таким образом, треугольник $\triangle ADE$ подобен треугольнику $\triangle ABC$ по двум углам.</p><p>Из подобия треугольников следует пропорциональность их сторон:</p><p>$\frac{AD}{AB} = \frac{AE}{AC} = \frac{DE}{BC}$</p><p>Коэффициент подобия $k = \frac{AB}{AD}$.</p><p>Из этой пропорции выразим искомую сторону $BC$:</p><p>$BC = DE \cdot \frac{AB}{AD}$</p><p>Найдем отношение $\frac{AB}{AD}$. Точка $D$ лежит на отрезке $AB$, поэтому $AB = AD + DB$.</p><p>По условию дано отношение $\frac{BD}{DA} = \frac{2}{3}$. Отсюда можно выразить $BD$ через $AD$:</p><p>$BD = \frac{2}{3} AD$</p><p>Подставим это в выражение для $AB$:</p><p>$AB = AD + \frac{2}{3} AD = (1 + \frac{2}{3}) AD = \frac{5}{3} AD$</p><p>Теперь найдем отношение $\frac{AB}{AD}$:</p><p>$\frac{AB}{AD} = \frac{\frac{5}{3} AD}{AD} = \frac{5}{3}$</p><p>Наконец, подставим все известные значения в формулу для $BC$. Нам дано, что $DE = 5$ см.</p><p>$BC = 5 \cdot \frac{5}{3} = \frac{25}{3}$ см.</p><p><strong>Ответ:</strong> $\frac{25}{3}$ см.</p>"
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "next" => array:2 [
      "refs" => "744444"
      "type" => "task"
    ]
    "previous" => array:2 [
      "refs" => "744442"
      "type" => "task"
    ]
    "book" => Illuminate\Database\Eloquent\Collection {#1164
      #items: array:1 [
        0 => App\Models\Book {#1165
          #connection: "mysql"
          #table: "books"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: false
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:50 [
            "id" => 36
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_tree_default_status" => "tasks"
            "field_pages_status" => null
            "field_subject" => Illuminate\Database\Eloquent\Collection {#1166
              #items: array:1 [
                0 => App\Models\Term {#1167
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:10 [ …10]
                  #original: array:10 [ …10]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_class" => Illuminate\Database\Eloquent\Collection {#1168
              #items: array:2 [
                0 => App\Models\Term {#1169
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                1 => App\Models\Term {#1170
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_publisher" => Illuminate\Database\Eloquent\Collection {#1171
              #items: array:1 [
                0 => App\Models\Term {#1172
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_author" => Illuminate\Database\Eloquent\Collection {#1173
              #items: array:5 [
                0 => App\Models\Term {#1174
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:12 [ …12]
                  #original: array:12 [ …12]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                1 => App\Models\Term {#1175
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:12 [ …12]
                  #original: array:12 [ …12]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                2 => App\Models\Term {#1176
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:12 [ …12]
                  #original: array:12 [ …12]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                3 => App\Models\Term {#1177
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:12 [ …12]
                  #original: array:12 [ …12]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                4 => App\Models\Term {#1178
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:12 [ …12]
                  #original: array:12 [ …12]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1179
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_book_type" => Illuminate\Database\Eloquent\Collection {#1180
              #items: array:1 [
                0 => App\Models\Term {#1181
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:10 [ …10]
                  #original: array:10 [ …10]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_country" => Illuminate\Database\Eloquent\Collection {#1182
              #items: array:1 [
                0 => App\Models\Term {#1183
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_city" => Illuminate\Database\Eloquent\Collection {#1184
              #items: array:1 [
                0 => App\Models\Term {#1185
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_series" => Illuminate\Database\Eloquent\Collection {#1186
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_umk" => Illuminate\Database\Eloquent\Collection {#1187
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1188
              #items: array:1 [
                0 => App\Models\Term {#1189
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1190
              #items: array:1 [
                0 => App\Models\Term {#1191
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:10 [ …10]
                  #original: array:10 [ …10]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_publication_number" => "11"
            "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1192
              #items: array:1 [
                0 => App\Models\Term {#1193
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1194
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_under_the_edition_degree" => null
            "field_cover_description" => "с ромбами"
            "field_publication_year" => "2019"
            "field_publication_year_until" => null
            "field_part" => ""
            "field_part_writing" => ""
            "field_second_foreign_language" => null
            "field_for_whom" => "Учебник для общеобразовательных организаций"
            "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
            "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
            "field_link_to_source" => null
            "field_tasks_count" => "1147"
            "field_priority" => "12"
            "field_default_folder" => "/geometrija_10/atanasjan-u23/"
            "field_isbn" => "978-5-09-103606-0 (2023)"
            "field_cover" => array:1 [
              0 => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
            ]
            "field_cover_alts" => array:1 [
              0 => ""
            ]
            "field_covers" => array:1 [
              0 => array:4 [
                "path" => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
                "alt" => ""
                "width" => "1200"
                "height" => "1661"
              ]
            ]
            "field_popular_book" => null
            "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1195
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_new_book" => Illuminate\Database\Eloquent\Collection {#1196
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_old_book" => Illuminate\Database\Eloquent\Collection {#1197
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
            "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1198
              #items: array:1 [
                0 => App\Models\Term {#1199
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "breadcrumbs" => array:3 [
              "class" => 381
              "subject" => 543
              "class_subject" => 392
            ]
          ]
          #original: array:50 [
            "id" => 36
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_tree_default_status" => "tasks"
            "field_pages_status" => null
            "field_subject" => Illuminate\Database\Eloquent\Collection {#1166}
            "field_class" => Illuminate\Database\Eloquent\Collection {#1168}
            "field_publisher" => Illuminate\Database\Eloquent\Collection {#1171}
            "field_author" => Illuminate\Database\Eloquent\Collection {#1173}
            "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1179}
            "field_book_type" => Illuminate\Database\Eloquent\Collection {#1180}
            "field_country" => Illuminate\Database\Eloquent\Collection {#1182}
            "field_city" => Illuminate\Database\Eloquent\Collection {#1184}
            "field_series" => Illuminate\Database\Eloquent\Collection {#1186}
            "field_umk" => Illuminate\Database\Eloquent\Collection {#1187}
            "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1188}
            "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1190}
            "field_publication_number" => "11"
            "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1192}
            "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1194}
            "field_under_the_edition_degree" => null
            "field_cover_description" => "с ромбами"
            "field_publication_year" => "2019"
            "field_publication_year_until" => null
            "field_part" => ""
            "field_part_writing" => ""
            "field_second_foreign_language" => null
            "field_for_whom" => "Учебник для общеобразовательных организаций"
            "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
            "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
            "field_link_to_source" => null
            "field_tasks_count" => "1147"
            "field_priority" => "12"
            "field_default_folder" => "/geometrija_10/atanasjan-u23/"
            "field_isbn" => "978-5-09-103606-0 (2023)"
            "field_cover" => array:1 [
              0 => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
            ]
            "field_cover_alts" => array:1 [
              0 => ""
            ]
            "field_covers" => array:1 [
              0 => array:4 [
                "path" => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
                "alt" => ""
                "width" => "1200"
                "height" => "1661"
              ]
            ]
            "field_popular_book" => null
            "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1195}
            "field_new_book" => Illuminate\Database\Eloquent\Collection {#1196}
            "field_old_book" => Illuminate\Database\Eloquent\Collection {#1197}
            "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
            "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1198}
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "breadcrumbs" => array:3 [
              "class" => 381
              "subject" => 543
              "class_subject" => 392
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "page" => Illuminate\Database\Eloquent\Collection {#1579
      #items: array:1 [
        0 => App\Models\BookPage {#1203
          #connection: "mysql"
          #table: "book_pages"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:21 [
            "id" => 933796
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_page_start" => "14"
            "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/page-14"
            "field_display_title" => "14"
            "field_folder" => "1"
            "field_image_name" => "14"
            "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1207
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_weight" => "0"
            "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1206
              #items: array:1 [
                0 => App\Models\Book {#1208
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [ …50]
                  #original: array:50 [ …50]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "edition_groups" => Illuminate\Database\Eloquent\Collection {#1243
              #items: []
              #escapeWhenCastingToString: false
            }
            "content" => Illuminate\Database\Eloquent\Collection {#1244
              #items: array:1 [
                0 => App\Models\Element {#1245
                  #connection: "mysql"
                  #table: "elements"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "next" => array:2 [
              "refs" => "933797"
              "type" => "book_page"
            ]
            "previous" => array:2 [
              "refs" => "933795"
              "type" => "book_page"
            ]
            "tasks" => Illuminate\Database\Eloquent\Collection {#1253
              #items: array:11 [
                0 => App\Models\Task {#1254
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                1 => App\Models\Task {#1389
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                2 => App\Models\Task {#1408
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                3 => App\Models\Task {#1427
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                4 => App\Models\Task {#1446
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                5 => App\Models\Task {#1465
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                6 => App\Models\Task {#1484
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                7 => App\Models\Task {#1503
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                8 => App\Models\Task {#1522
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                9 => App\Models\Task {#1541
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                10 => App\Models\Task {#1560
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:21 [
            "id" => 933796
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_page_start" => "14"
            "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/page-14"
            "field_display_title" => "14"
            "field_folder" => "1"
            "field_image_name" => "14"
            "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1207}
            "field_weight" => "0"
            "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1206}
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "edition_groups" => Illuminate\Database\Eloquent\Collection {#1243}
            "content" => Illuminate\Database\Eloquent\Collection {#1244}
            "next" => array:2 [
              "refs" => "933797"
              "type" => "book_page"
            ]
            "previous" => array:2 [
              "refs" => "933795"
              "type" => "book_page"
            ]
            "tasks" => Illuminate\Database\Eloquent\Collection {#1253}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
  ]
  #original: array:24 [
    "id" => 744443
    "created_at" => "2026-04-10 13:58:26"
    "updated_at" => null
    "field_page_start" => "14"
    "field_page_end" => null
    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/00-28"
    "field_display_title" => "28"
    "field_outside_task" => null
    "field_task_type" => Illuminate\Database\Eloquent\Collection {#331}
    "field_metatags_title" => null
    "field_metatags_description" => null
    "field_h1" => null
    "field_description_top" => null
    "field_description_bottom" => null
    "field_match" => null
    "breadcrumbs" => []
    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1026}
    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#342}
    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1069}
    "content" => Illuminate\Database\Eloquent\Collection {#1115}
    "next" => array:2 [
      "refs" => "744444"
      "type" => "task"
    ]
    "previous" => array:2 [
      "refs" => "744442"
      "type" => "task"
    ]
    "book" => Illuminate\Database\Eloquent\Collection {#1164}
    "page" => array:2 [
      "refs" => "933796"
      "type" => "book_page"
    ]
  ]
  #changes: []
  #casts: []
  #classCastCache: []
  #attributeCastCache: []
  #dateFormat: null
  #appends: []
  #dispatchesEvents: []
  #observables: []
  #relations: []
  #touches: []
  +timestamps: true
  +usesUniqueIds: false
  #hidden: []
  #visible: []
  #fillable: []
  #guarded: array:1 [
    0 => "*"
  ]
}
№28 (с. 14)
Условие. №28 (с. 14)
скриншот условия
Геометрия, 10-11 класс Учебник, авторы: Атанасян Левон Сергеевич, Бутузов Валентин Фёдорович, Кадомцев Сергей Борисович, Позняк Эдуард Генрихович, Киселёва Людмила Сергеевна, издательство Просвещение, Москва, 2019, коричневого цвета, страница 14, номер 28, Условие

28. На сторонах АВ и АС треугольника ABC взяты соответственно точки D и Е так, что длина отрезка DE равна 5 см и BDDA = 23. Плоскость α проходит через точки В и С и параллельна отрезку DE. Найдите длину отрезка ВС.

Решение 2. №28 (с. 14)
Геометрия, 10-11 класс Учебник, авторы: Атанасян Левон Сергеевич, Бутузов Валентин Фёдорович, Кадомцев Сергей Борисович, Позняк Эдуард Генрихович, Киселёва Людмила Сергеевна, издательство Просвещение, Москва, 2019, коричневого цвета, страница 14, номер 28, Решение 2
Решение 3. №28 (с. 14)
Геометрия, 10-11 класс Учебник, авторы: Атанасян Левон Сергеевич, Бутузов Валентин Фёдорович, Кадомцев Сергей Борисович, Позняк Эдуард Генрихович, Киселёва Людмила Сергеевна, издательство Просвещение, Москва, 2019, коричневого цвета, страница 14, номер 28, Решение 3
Решение 4. №28 (с. 14)
Геометрия, 10-11 класс Учебник, авторы: Атанасян Левон Сергеевич, Бутузов Валентин Фёдорович, Кадомцев Сергей Борисович, Позняк Эдуард Генрихович, Киселёва Людмила Сергеевна, издательство Просвещение, Москва, 2019, коричневого цвета, страница 14, номер 28, Решение 4
Решение 5. №28 (с. 14)
Решение 6. №28 (с. 14)

По условию задачи, точки D и E лежат на сторонах AB и AC треугольника ABC соответственно. Плоскость $\alpha$ проходит через точки B и C, значит, прямая BC лежит в плоскости $\alpha$. Также дано, что плоскость $\alpha$ параллельна отрезку DE.

Рассмотрим плоскость, в которой лежит треугольник ABC. Эта плоскость содержит прямую DE. Согласно теореме о параллельности прямой и плоскости, если плоскость (в данном случае, плоскость $\triangle ABC$) проходит через прямую (DE), параллельную другой плоскости ($\alpha$), и пересекает эту плоскость, то линия пересечения этих плоскостей (прямая BC) параллельна данной прямой (DE).

Следовательно, мы можем утверждать, что отрезок $DE$ параллелен отрезку $BC$ ($DE \parallel BC$).

Теперь рассмотрим треугольники $\triangle ADE$ и $\triangle ABC$.

1. Угол $\angle A$ является общим для обоих треугольников.

2. Угол $\angle ADE$ равен углу $\angle ABC$ как соответственные углы при параллельных прямых $DE$ и $BC$ и секущей $AB$.

Таким образом, треугольник $\triangle ADE$ подобен треугольнику $\triangle ABC$ по двум углам.

Из подобия треугольников следует пропорциональность их сторон:

$\frac{AD}{AB} = \frac{AE}{AC} = \frac{DE}{BC}$

Коэффициент подобия $k = \frac{AB}{AD}$.

Из этой пропорции выразим искомую сторону $BC$:

$BC = DE \cdot \frac{AB}{AD}$

Найдем отношение $\frac{AB}{AD}$. Точка $D$ лежит на отрезке $AB$, поэтому $AB = AD + DB$.

По условию дано отношение $\frac{BD}{DA} = \frac{2}{3}$. Отсюда можно выразить $BD$ через $AD$:

$BD = \frac{2}{3} AD$

Подставим это в выражение для $AB$:

$AB = AD + \frac{2}{3} AD = (1 + \frac{2}{3}) AD = \frac{5}{3} AD$

Теперь найдем отношение $\frac{AB}{AD}$:

$\frac{AB}{AD} = \frac{\frac{5}{3} AD}{AD} = \frac{5}{3}$

Наконец, подставим все известные значения в формулу для $BC$. Нам дано, что $DE = 5$ см.

$BC = 5 \cdot \frac{5}{3} = \frac{25}{3}$ см.

Ответ: $\frac{25}{3}$ см.

Помогло решение? Оставьте отзыв в комментариях ниже.

Присоединяйтесь к Телеграм-группе @top_gdz

Присоединиться

Мы подготовили для вас ответ c подробным объяснением домашего задания по геометрии за 10-11 класс, для упражнения номер 28 расположенного на странице 14 к учебнику 2019 года издания для учащихся школ и гимназий.

Теперь на нашем сайте ГДЗ.ТОП вы всегда легко и бесплатно найдёте условие с правильным ответом на вопрос «Как решить ДЗ» и «Как сделать» задание по геометрии к упражнению №28 (с. 14), авторов: Атанасян (Левон Сергеевич), Бутузов (Валентин Фёдорович), Кадомцев (Сергей Борисович), Позняк (Эдуард Генрихович), Киселёва (Людмила Сергеевна), ФГОС (старый) базовый и углублённый уровень обучения учебного пособия издательства Просвещение.