Номер 45, страница 20 - 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 2. Взаимное расположение прямых в пространстве - номер 45, страница 20.

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                          #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 {#1139
                      #items: array:5 [
                        0 => App\Models\Term {#1140
                          #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 {#1141
                          #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 {#1142
                          #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 {#1143
                          #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 {#1144
                          #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 {#1145
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1146
                      #items: array:1 [
                        0 => App\Models\Term {#1147
                          #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 {#1148
                      #items: array:1 [
                        0 => App\Models\Term {#1149
                          #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 {#1150
                      #items: array:1 [
                        0 => App\Models\Term {#1151
                          #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 {#1152
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1153
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1154
                      #items: array:1 [
                        0 => App\Models\Term {#1155
                          #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 {#1156
                      #items: array:1 [
                        0 => App\Models\Term {#1157
                          #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 {#1158
                      #items: array:1 [
                        0 => App\Models\Term {#1159
                          #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 {#1160
                      #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 {#1161
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1162
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1163
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1164
                      #items: array:1 [
                        0 => App\Models\Term {#1165
                          #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 {#1133}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1134}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1137}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1139}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1145}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1146}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1148}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1150}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1152}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1153}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1154}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1156}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1158}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1160}
                    "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 {#1161}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1162}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1163}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1164}
                    "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
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1166
              #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 {#1132}
            "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 {#1168}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1166}
          ]
          #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\Branch {#1167
          #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" => 744369
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Взаимное расположение прямых в пространстве"
            "field_branch_order" => "2"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1172
              #items: array:1 [
                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: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: []
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                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "15"
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            "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 {#1171
              #items: array:1 [
                0 => App\Models\Book {#1131}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1170
              #items: array:1 [
                0 => App\Models\Branch {#1034}
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 744369
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Взаимное расположение прямых в пространстве"
            "field_branch_order" => "2"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1172}
            "field_page_start" => "15"
            "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 {#1171}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1170}
          ]
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            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "content" => Illuminate\Database\Eloquent\Collection {#1118
      #items: array:6 [
        0 => App\Models\Element {#1179
          #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" => 938694
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1188
              #items: array:1 [
                0 => App\Models\Edition {#1180
                  #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 {#1182 …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 {#1183 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1184 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1185 …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 {#1182 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text, image"
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                    "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 {#1183 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1184 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1185 …2}
                    "field_content_source" => null
                  ]
                  #changes: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  +timestamps: true
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                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "text" => "<p> <b>45</b>. Прямая <i>а</i> параллельна стороне ВС параллелограмма ABCD и не лежит в плоскости параллелограмма. Докажите, что а и CD — скрещивающиеся прямые, и найдите угол между ними, если один из углов параллелограмма равен: </p> <p> а) 50°; </p> <p> б) 121°. </p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "45-1.jpg"
                "alt" => null
                "width" => "1545"
                "height" => 320
                "path" => "/media/geometrija_10/atanasjan-u23/0-00/45-1.webp?ts=1739436312"
              ]
            ]
          ]
          #original: array:7 [
            "id" => 938694
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1188}
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "text" => "<p> <b>45</b>. Прямая <i>а</i> параллельна стороне ВС параллелограмма ABCD и не лежит в плоскости параллелограмма. Докажите, что а и CD — скрещивающиеся прямые, и найдите угол между ними, если один из углов параллелограмма равен: </p> <p> а) 50°; </p> <p> б) 121°. </p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "45-1.jpg"
                "alt" => null
                "width" => "1545"
                "height" => 320
                "path" => "/media/geometrija_10/atanasjan-u23/0-00/45-1.webp?ts=1739436312"
              ]
            ]
          ]
          #changes: []
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          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
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          #hidden: []
          #visible: []
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          #guarded: array:1 [
            0 => "*"
          ]
        }
        1 => App\Models\Element {#1194
          #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" => 939707
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1204
              #items: array:1 [
                0 => App\Models\Edition {#1195
                  #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" => 2317
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 2"
                    "field_order" => "3"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1198 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "image"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => "0"
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Неизвестный"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "2-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1199 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1200 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1201 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 2317
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 2"
                    "field_order" => "3"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1198 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "image"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => "0"
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Неизвестный"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "2-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1199 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1200 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1201 …2}
                    "field_content_source" => null
                  ]
                  #changes: []
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                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "img" => array:2 [
              0 => array:5 [
                "name" => "45-1.png"
                "alt" => null
                "width" => "694"
                "height" => 4723
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/45-1.webp?ts=1739440860"
              ]
              1 => array:5 [
                "name" => "45-2.png"
                "alt" => null
                "width" => "694"
                "height" => 4167
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/45-2.webp?ts=1739440860"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 939707
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1204}
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "img" => array:2 [
              0 => array:5 [
                "name" => "45-1.png"
                "alt" => null
                "width" => "694"
                "height" => 4723
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/45-1.webp?ts=1739440860"
              ]
              1 => array:5 [
                "name" => "45-2.png"
                "alt" => null
                "width" => "694"
                "height" => 4167
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/45-2.webp?ts=1739440860"
              ]
            ]
          ]
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            0 => "*"
          ]
        }
        2 => App\Models\Element {#1186
          #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" => 939449
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1196
              #items: array:1 [
                0 => App\Models\Edition {#1187
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
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                  #escapeWhenCastingToString: false
                  #attributes: array:21 [
                    "id" => 2318
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 3"
                    "field_order" => "4"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1190 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "image"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => "0"
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Неизвестный"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "3-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1191 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1192 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1193 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 2318
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 3"
                    "field_order" => "4"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1190 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "image"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => "0"
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Неизвестный"
                    "field_moderator" => "pasha"
                     …8
                  ]
                  #changes: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "45-1.jpg"
                "alt" => null
                "width" => "1351"
                "height" => 1005
                "path" => "/media/geometrija_10/atanasjan-u23/3-00/45-1.webp?ts=1739436488"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 939449
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1196}
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "45-1.jpg"
                "alt" => null
                "width" => "1351"
                "height" => 1005
                "path" => "/media/geometrija_10/atanasjan-u23/3-00/45-1.webp?ts=1739436488"
              ]
            ]
          ]
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          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        3 => App\Models\Element {#1202
          #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" => 939762
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1212
              #items: array:1 [
                0 => App\Models\Edition {#1203
                  #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]
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                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
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                  +timestamps: true
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                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "img" => array:2 [
              0 => array:5 [
                "name" => "45-1.jpg"
                "alt" => null
                "width" => "1161"
                "height" => 285
                "path" => "/media/geometrija_10/atanasjan-u23/4-00/45-1.webp?ts=1739436333"
              ]
              1 => array:5 [
                "name" => "45-2.jpg"
                "alt" => null
                "width" => "1161"
                "height" => 285
                "path" => "/media/geometrija_10/atanasjan-u23/4-00/45-2.webp?ts=1739436333"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 939762
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1212}
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "img" => array:2 [
              0 => array:5 [
                "name" => "45-1.jpg"
                "alt" => null
                "width" => "1161"
                "height" => 285
                "path" => "/media/geometrija_10/atanasjan-u23/4-00/45-1.webp?ts=1739436333"
              ]
              1 => array:5 [
                "name" => "45-2.jpg"
                "alt" => null
                "width" => "1161"
                "height" => 285
                "path" => "/media/geometrija_10/atanasjan-u23/4-00/45-2.webp?ts=1739436333"
              ]
            ]
          ]
          #changes: []
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          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
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          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        4 => App\Models\Element {#1210
          #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" => 939893
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1220
              #items: array:1 [
                0 => App\Models\Edition {#1211
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
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                  #withCount: []
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                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [ …21]
                  #original: array:21 [ …21]
                  #changes: []
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                  #dateFormat: null
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
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              "refs" => "744460"
              "type" => "task"
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                "width" => "1329"
                "height" => 907
                "path" => "/media/geometrija_10/atanasjan-u23/5-00/45-1.webp?ts=1739436341"
              ]
            ]
          ]
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            "id" => 939893
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1220}
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
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            0 => "*"
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        }
        5 => App\Models\Element {#1218
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
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          #attributes: array:6 [
            "id" => 1351773
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1228
              #items: array:1 [
                0 => App\Models\Edition {#1219
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
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                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
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                  #attributes: array:21 [ …21]
                  #original: array:21 [ …21]
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              ]
              #escapeWhenCastingToString: false
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            "task" => array:2 [
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            "text" => "<p>Обозначим плоскость параллелограмма $ABCD$ как $\alpha$.</p><p><strong>Доказательство того, что прямые $a$ и $CD$ скрещивающиеся:</strong></p><p>Скрещивающиеся прямые — это прямые, которые не лежат в одной плоскости, то есть они не пересекаются и не параллельны.</p><ol><li> <strong>Докажем, что $a$ и $CD$ не пересекаются.</strong><p>По условию, прямая $a$ не лежит в плоскости параллелограмма $\alpha$. Прямая $CD$ полностью лежит в плоскости $\alpha$. По условию, прямая $a$ параллельна стороне $BC$ ($a \parallel BC$), которая также лежит в плоскости $\alpha$. По признаку параллельности прямой и плоскости, если прямая, не лежащая в плоскости, параллельна какой-либо прямой в этой плоскости, то она параллельна и самой плоскости. Следовательно, $a \parallel \alpha$.</p><p>Раз прямая $a$ параллельна плоскости $\alpha$, она не имеет с ней общих точек. Поскольку прямая $CD$ лежит в плоскости $\alpha$, прямая $a$ не может пересечь прямую $CD$.</p></li> <li> <strong>Докажем, что $a$ и $CD$ не параллельны.</strong><p>Предположим, что $a \parallel CD$. По условию мы знаем, что $a \parallel BC$. Из этих двух предположений по свойству транзитивности параллельных прямых следовало бы, что $BC \parallel CD$. Но $BC$ и $CD$ — это смежные стороны параллелограмма $ABCD$, они пересекаются в точке $C$ и не могут быть параллельными. Следовательно, наше предположение неверно, и прямые $a$ и $CD$ не параллельны.</p></li></ol><p>Так как прямые $a$ и $CD$ не пересекаются и не параллельны, они являются скрещивающимися, что и требовалось доказать.</p><p><strong>Нахождение угла между прямыми $a$ и $CD$:</strong></p><p>Угол между скрещивающимися прямыми — это угол между двумя пересекающимися прямыми, которые соответственно параллельны данным скрещивающимся прямым.</p><p>Поскольку по условию $a \parallel BC$, угол между скрещивающимися прямыми $a$ и $CD$ равен углу между прямыми $BC$ и $CD$. Этот угол равен меньшему из двух смежных углов, образованных сторонами $BC$ и $CD$, то есть он равен $\angle BCD$ или $180^\circ - \angle BCD$.</p><p>В параллелограмме сумма углов, прилежащих к одной стороне, равна $180^\circ$.</p><p><strong>а)</strong> Один из углов параллелограмма равен $50^\circ$.</p><p>Так как $50^\circ &lt; 90^\circ$, это острый угол параллелограмма. Другой угол, прилежащий к той же стороне, будет тупым: $180^\circ - 50^\circ = 130^\circ$. Угол $\angle BCD$ может быть либо острым, либо тупым.</p><ul><li> Если $\angle BCD = 50^\circ$, то угол между прямыми $BC$ и $CD$ равен $50^\circ$. </li> <li> Если $\angle BCD = 130^\circ$, то угол между прямыми $BC$ и $CD$ равен $180^\circ - 130^\circ = 50^\circ$. </li></ul><p>В обоих случаях угол между прямыми $BC$ и $CD$, а значит и между прямыми $a$ и $CD$, равен $50^\circ$.</p><p><strong>Ответ:</strong> $50^\circ$.</p><p><strong>б)</strong> Один из углов параллелограмма равен $121^\circ$.</p><p>Так как $121^\circ > 90^\circ$, это тупой угол параллелограмма. Другой угол, прилежащий к той же стороне, будет острым: $180^\circ - 121^\circ = 59^\circ$. Угол $\angle BCD$ может быть либо острым, либо тупым.</p><ul><li> Если $\angle BCD = 121^\circ$, то угол между прямыми $BC$ и $CD$ равен меньшему из смежных углов: $180^\circ - 121^\circ = 59^\circ$. </li> <li> Если $\angle BCD = 59^\circ$, то угол между прямыми $BC$ и $CD$ равен $59^\circ$. </li></ul><p>В обоих случаях угол между прямыми $BC$ и $CD$, а значит и между прямыми $a$ и $CD$, равен $59^\circ$.</p><p><strong>Ответ:</strong> $59^\circ$.</p>"
          ]
          #original: array:6 [
            "id" => 1351773
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1228}
            "task" => array:2 [
              "refs" => "744460"
              "type" => "task"
            ]
            "text" => "<p>Обозначим плоскость параллелограмма $ABCD$ как $\alpha$.</p><p><strong>Доказательство того, что прямые $a$ и $CD$ скрещивающиеся:</strong></p><p>Скрещивающиеся прямые — это прямые, которые не лежат в одной плоскости, то есть они не пересекаются и не параллельны.</p><ol><li> <strong>Докажем, что $a$ и $CD$ не пересекаются.</strong><p>По условию, прямая $a$ не лежит в плоскости параллелограмма $\alpha$. Прямая $CD$ полностью лежит в плоскости $\alpha$. По условию, прямая $a$ параллельна стороне $BC$ ($a \parallel BC$), которая также лежит в плоскости $\alpha$. По признаку параллельности прямой и плоскости, если прямая, не лежащая в плоскости, параллельна какой-либо прямой в этой плоскости, то она параллельна и самой плоскости. Следовательно, $a \parallel \alpha$.</p><p>Раз прямая $a$ параллельна плоскости $\alpha$, она не имеет с ней общих точек. Поскольку прямая $CD$ лежит в плоскости $\alpha$, прямая $a$ не может пересечь прямую $CD$.</p></li> <li> <strong>Докажем, что $a$ и $CD$ не параллельны.</strong><p>Предположим, что $a \parallel CD$. По условию мы знаем, что $a \parallel BC$. Из этих двух предположений по свойству транзитивности параллельных прямых следовало бы, что $BC \parallel CD$. Но $BC$ и $CD$ — это смежные стороны параллелограмма $ABCD$, они пересекаются в точке $C$ и не могут быть параллельными. Следовательно, наше предположение неверно, и прямые $a$ и $CD$ не параллельны.</p></li></ol><p>Так как прямые $a$ и $CD$ не пересекаются и не параллельны, они являются скрещивающимися, что и требовалось доказать.</p><p><strong>Нахождение угла между прямыми $a$ и $CD$:</strong></p><p>Угол между скрещивающимися прямыми — это угол между двумя пересекающимися прямыми, которые соответственно параллельны данным скрещивающимся прямым.</p><p>Поскольку по условию $a \parallel BC$, угол между скрещивающимися прямыми $a$ и $CD$ равен углу между прямыми $BC$ и $CD$. Этот угол равен меньшему из двух смежных углов, образованных сторонами $BC$ и $CD$, то есть он равен $\angle BCD$ или $180^\circ - \angle BCD$.</p><p>В параллелограмме сумма углов, прилежащих к одной стороне, равна $180^\circ$.</p><p><strong>а)</strong> Один из углов параллелограмма равен $50^\circ$.</p><p>Так как $50^\circ &lt; 90^\circ$, это острый угол параллелограмма. Другой угол, прилежащий к той же стороне, будет тупым: $180^\circ - 50^\circ = 130^\circ$. Угол $\angle BCD$ может быть либо острым, либо тупым.</p><ul><li> Если $\angle BCD = 50^\circ$, то угол между прямыми $BC$ и $CD$ равен $50^\circ$. </li> <li> Если $\angle BCD = 130^\circ$, то угол между прямыми $BC$ и $CD$ равен $180^\circ - 130^\circ = 50^\circ$. </li></ul><p>В обоих случаях угол между прямыми $BC$ и $CD$, а значит и между прямыми $a$ и $CD$, равен $50^\circ$.</p><p><strong>Ответ:</strong> $50^\circ$.</p><p><strong>б)</strong> Один из углов параллелограмма равен $121^\circ$.</p><p>Так как $121^\circ > 90^\circ$, это тупой угол параллелограмма. Другой угол, прилежащий к той же стороне, будет острым: $180^\circ - 121^\circ = 59^\circ$. Угол $\angle BCD$ может быть либо острым, либо тупым.</p><ul><li> Если $\angle BCD = 121^\circ$, то угол между прямыми $BC$ и $CD$ равен меньшему из смежных углов: $180^\circ - 121^\circ = 59^\circ$. </li> <li> Если $\angle BCD = 59^\circ$, то угол между прямыми $BC$ и $CD$ равен $59^\circ$. </li></ul><p>В обоих случаях угол между прямыми $BC$ и $CD$, а значит и между прямыми $a$ и $CD$, равен $59^\circ$.</p><p><strong>Ответ:</strong> $59^\circ$.</p>"
          ]
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    "book" => Illuminate\Database\Eloquent\Collection {#1177
      #items: array:1 [
        0 => App\Models\Book {#1131}
      ]
      #escapeWhenCastingToString: false
    }
    "page" => Illuminate\Database\Eloquent\Collection {#1459
      #items: array:1 [
        0 => App\Models\BookPage {#1032
          #connection: "mysql"
          #table: "book_pages"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
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          +preventsLazyLoading: false
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          #escapeWhenCastingToString: false
          #attributes: array:21 [
            "id" => 933802
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_page_start" => "20"
            "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/page-20"
            "field_display_title" => "20"
            "field_folder" => "1"
            "field_image_name" => "20"
            "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1023
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_weight" => "0"
            "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1026
              #items: array:1 [
                0 => App\Models\Book {#1088
                  #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: []
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                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
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                  #touches: []
                  +timestamps: true
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                  #hidden: []
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                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
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            "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 {#1114
              #items: []
              #escapeWhenCastingToString: false
            }
            "content" => Illuminate\Database\Eloquent\Collection {#1116
              #items: array:1 [
                0 => App\Models\Element {#1115
                  #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: []
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                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "next" => array:2 [
              "refs" => "933803"
              "type" => "book_page"
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              "refs" => "933801"
              "type" => "book_page"
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            "tasks" => Illuminate\Database\Eloquent\Collection {#1122
              #items: array:10 [
                0 => App\Models\Task {#1174
                  #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: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                1 => App\Models\Task {#1286
                  #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: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                2 => App\Models\Task {#1305
                  #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: []
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                3 => App\Models\Task {#1324
                  #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: []
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                  #attributeCastCache: []
                  #dateFormat: null
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                4 => App\Models\Task {#1343
                  #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: []
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                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                5 => App\Models\Task {#1362
                  #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]
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                  #attributeCastCache: []
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                  +timestamps: true
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№45 (с. 20)
Условие. №45 (с. 20)
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 20, номер 45, Условие

45. Прямая а параллельна стороне ВС параллелограмма ABCD и не лежит в плоскости параллелограмма. Докажите, что а и CD — скрещивающиеся прямые, и найдите угол между ними, если один из углов параллелограмма равен:

а) 50°;

б) 121°.

Решение 2. №45 (с. 20)
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 20, номер 45, Решение 2
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 20, номер 45, Решение 2 (продолжение 2)
Решение 3. №45 (с. 20)
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 20, номер 45, Решение 3
Решение 4. №45 (с. 20)
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 20, номер 45, Решение 4
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 20, номер 45, Решение 4 (продолжение 2)
Решение 5. №45 (с. 20)
Решение 6. №45 (с. 20)

Обозначим плоскость параллелограмма $ABCD$ как $\alpha$.

Доказательство того, что прямые $a$ и $CD$ скрещивающиеся:

Скрещивающиеся прямые — это прямые, которые не лежат в одной плоскости, то есть они не пересекаются и не параллельны.

  1. Докажем, что $a$ и $CD$ не пересекаются.

    По условию, прямая $a$ не лежит в плоскости параллелограмма $\alpha$. Прямая $CD$ полностью лежит в плоскости $\alpha$. По условию, прямая $a$ параллельна стороне $BC$ ($a \parallel BC$), которая также лежит в плоскости $\alpha$. По признаку параллельности прямой и плоскости, если прямая, не лежащая в плоскости, параллельна какой-либо прямой в этой плоскости, то она параллельна и самой плоскости. Следовательно, $a \parallel \alpha$.

    Раз прямая $a$ параллельна плоскости $\alpha$, она не имеет с ней общих точек. Поскольку прямая $CD$ лежит в плоскости $\alpha$, прямая $a$ не может пересечь прямую $CD$.

  2. Докажем, что $a$ и $CD$ не параллельны.

    Предположим, что $a \parallel CD$. По условию мы знаем, что $a \parallel BC$. Из этих двух предположений по свойству транзитивности параллельных прямых следовало бы, что $BC \parallel CD$. Но $BC$ и $CD$ — это смежные стороны параллелограмма $ABCD$, они пересекаются в точке $C$ и не могут быть параллельными. Следовательно, наше предположение неверно, и прямые $a$ и $CD$ не параллельны.

Так как прямые $a$ и $CD$ не пересекаются и не параллельны, они являются скрещивающимися, что и требовалось доказать.

Нахождение угла между прямыми $a$ и $CD$:

Угол между скрещивающимися прямыми — это угол между двумя пересекающимися прямыми, которые соответственно параллельны данным скрещивающимся прямым.

Поскольку по условию $a \parallel BC$, угол между скрещивающимися прямыми $a$ и $CD$ равен углу между прямыми $BC$ и $CD$. Этот угол равен меньшему из двух смежных углов, образованных сторонами $BC$ и $CD$, то есть он равен $\angle BCD$ или $180^\circ - \angle BCD$.

В параллелограмме сумма углов, прилежащих к одной стороне, равна $180^\circ$.

а) Один из углов параллелограмма равен $50^\circ$.

Так как $50^\circ < 90^\circ$, это острый угол параллелограмма. Другой угол, прилежащий к той же стороне, будет тупым: $180^\circ - 50^\circ = 130^\circ$. Угол $\angle BCD$ может быть либо острым, либо тупым.

  • Если $\angle BCD = 50^\circ$, то угол между прямыми $BC$ и $CD$ равен $50^\circ$.
  • Если $\angle BCD = 130^\circ$, то угол между прямыми $BC$ и $CD$ равен $180^\circ - 130^\circ = 50^\circ$.

В обоих случаях угол между прямыми $BC$ и $CD$, а значит и между прямыми $a$ и $CD$, равен $50^\circ$.

Ответ: $50^\circ$.

б) Один из углов параллелограмма равен $121^\circ$.

Так как $121^\circ > 90^\circ$, это тупой угол параллелограмма. Другой угол, прилежащий к той же стороне, будет острым: $180^\circ - 121^\circ = 59^\circ$. Угол $\angle BCD$ может быть либо острым, либо тупым.

  • Если $\angle BCD = 121^\circ$, то угол между прямыми $BC$ и $CD$ равен меньшему из смежных углов: $180^\circ - 121^\circ = 59^\circ$.
  • Если $\angle BCD = 59^\circ$, то угол между прямыми $BC$ и $CD$ равен $59^\circ$.

В обоих случаях угол между прямыми $BC$ и $CD$, а значит и между прямыми $a$ и $CD$, равен $59^\circ$.

Ответ: $59^\circ$.

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