Номер 8, страница 237 - 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

Задачи для подготовки к ЕГЭ. 16 - номер 8, страница 237.

App\Models\Task {#1030 // resources/views/models/task/default.blade.php
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  #table: "tasks"
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                          #connection: "mysql"
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                            "created_at" => "2026-04-10 13:58:26"
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                            "created_at" => "2026-04-10 13:58:26"
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                        1 => App\Models\Term {#1053
                          #connection: "mysql"
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                        0 => App\Models\Term {#1055
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                    }
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1062
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1063
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                        0 => App\Models\Term {#1064
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                            "field_cases" => array:6 [ …6]
                            "field_plural_form" => null
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                          ]
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                      ]
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                        0 => App\Models\Term {#1066
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                            "field_translit" => "rossiya"
                          ]
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Россия"
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                    "field_city" => Illuminate\Database\Eloquent\Collection {#1067
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                        0 => App\Models\Term {#1068
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
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                          #withCount: []
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                          #attributes: array:6 [
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Москва"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "moskva"
                          ]
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Москва"
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                      ]
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                    }
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1070
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                      #escapeWhenCastingToString: false
                    }
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1071
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                        0 => App\Models\Term {#1072
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
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                          #attributes: array:6 [
                            "id" => 41
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
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                            "field_cases" => array:6 [ …6]
                            "field_translit" => "bazovyy i uglublennyy"
                          ]
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "базовый и углублённый"
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                            "field_translit" => "bazovyy i uglublennyy"
                          ]
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                            0 => "*"
                          ]
                        }
                      ]
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                    }
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1073
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                        0 => App\Models\Term {#1074
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
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                          #attributes: array:10 [
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                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "ФГОС (старый)"
                            "field_cases" => array:6 [ …6]
                            "field_color" => null
                            "field_end_year" => "2022"
                            "field_start_year" => "2019"
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                          ]
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                            "updated_at" => null
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                            "field_color" => null
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                          ]
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                        }
                      ]
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                    }
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1075
                      #items: array:1 [
                        0 => App\Models\Term {#1076
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
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                          #withCount: []
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                          +exists: true
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                          #attributes: array:6 [
                            "id" => 33
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "стереотипное"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "stereotipnoe"
                          ]
                          #original: array:6 [
                            "id" => 33
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "стереотипное"
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                            "field_translit" => "stereotipnoe"
                          ]
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                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
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                          #dispatchesEvents: []
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                      ]
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                    }
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1077
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
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                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
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                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
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                    "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 {#1078
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1079
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1080
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1081
                      #items: array:1 [
                        0 => App\Models\Term {#1082
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
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                          +exists: true
                          +wasRecentlyCreated: false
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                          #attributes: array:6 [
                            "id" => 51
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "коричневый"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "korichnevyy"
                          ]
                          #original: array:6 [
                            "id" => 51
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "коричневый"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "korichnevyy"
                          ]
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                      ]
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                    ]
                  ]
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                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
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                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1050}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1051}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1054}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1056}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1062}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1063}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1065}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1067}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1069}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1070}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1071}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1073}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1075}
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                    "field_cover_description" => "с ромбами"
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                    "field_publication_year_until" => null
                    "field_part" => ""
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                    "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"
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                    "field_cover" => array:1 [
                      0 => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
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                      0 => array:4 [
                        "path" => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
                        "alt" => ""
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                        "height" => "1661"
                      ]
                    ]
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                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1078}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1079}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1080}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1081}
                    "field_metatags_title" => null
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                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [
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                    ]
                  ]
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                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1083
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
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            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Задачи для подготовки к ЕГЭ"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1047}
            "field_page_start" => "229"
            "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 {#1085}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1083}
          ]
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          #attributeCastCache: []
          #dateFormat: null
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          #hidden: []
          #visible: []
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            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1119
      #items: array:2 [
        0 => App\Models\Branch {#1127
          #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" => 745563
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Задачи для подготовки к ЕГЭ"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1128
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "229"
            "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
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            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1129
              #items: array:1 [
                0 => App\Models\Book {#1048}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1130
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
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            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Задачи для подготовки к ЕГЭ"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1128}
            "field_page_start" => "229"
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            "field_display_branch_in_title" => "1"
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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 {#1129}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1130}
          ]
          #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 {#1131
          #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" => 745568
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "16"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1132
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "236"
            "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 {#1133
              #items: array:1 [
                0 => App\Models\Book {#1048}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1134
              #items: array:1 [
                0 => App\Models\Branch {#1045}
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 745568
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "16"
            "field_branch_order" => null
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1132}
            "field_page_start" => "236"
            "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 {#1133}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1134}
          ]
          #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 {#1038
      #items: array:4 [
        0 => App\Models\Element {#1107
          #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" => 940898
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1092
              #items: array:1 [
                0 => App\Models\Edition {#1090
                  #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 {#1084 …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 {#1118 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1088 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1040 …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 {#1084 …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 {#1118 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1088 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1040 …2}
                    "field_content_source" => 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
            }
            "task" => array:2 [
              "refs" => "745407"
              "type" => "task"
            ]
            "text" => "<p><strong>8.</strong> Углы A и C треугольника ABC равны 45° и 60°. Отрезки AM, BN и CK — высоты треугольника. Найдите отношение <span class="long"><span class="fraction"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mrow><mi>M</mi><mi>N</mi></mrow><mrow><mi>K</mi><mi>N</mi></mrow></mfrac></math></span>.</span></p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "8-1.jpg"
                "alt" => null
                "width" => "1534"
                "height" => 207
                "path" => "/media/geometrija_10/atanasjan-u23/0-eg-5/8-1.webp?ts=1739437033"
              ]
            ]
          ]
          #original: array:7 [
            "id" => 940898
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1092}
            "task" => array:2 [
              "refs" => "745407"
              "type" => "task"
            ]
            "text" => "<p><strong>8.</strong> Углы A и C треугольника ABC равны 45° и 60°. Отрезки AM, BN и CK — высоты треугольника. Найдите отношение <span class="long"><span class="fraction"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mrow><mi>M</mi><mi>N</mi></mrow><mrow><mi>K</mi><mi>N</mi></mrow></mfrac></math></span>.</span></p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "8-1.jpg"
                "alt" => null
                "width" => "1534"
                "height" => 207
                "path" => "/media/geometrija_10/atanasjan-u23/0-eg-5/8-1.webp?ts=1739437033"
              ]
            ]
          ]
          #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 {#1109
          #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" => 939590
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1099
              #items: array:1 [
                0 => App\Models\Edition {#1098
                  #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" => 2316
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 1"
                    "field_order" => "2"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1089 …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" => "Пелеванюк"
                    "field_moderator" => "filin"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "1-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1091 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1097 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1094 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 2316
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 1"
                    "field_order" => "2"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1089 …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" => "Пелеванюк"
                    "field_moderator" => "filin"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "1-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1091 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1097 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1094 …2}
                    "field_content_source" => 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
            }
            "task" => array:2 [
              "refs" => "745407"
              "type" => "task"
            ]
            "img" => array:2 [
              0 => array:5 [
                "name" => "8-1.jpg"
                "alt" => null
                "width" => "2001"
                "height" => 3253
                "path" => "/media/geometrija_10/atanasjan-u23/1-eg-5/8-1.webp?ts=1739436213"
              ]
              1 => array:5 [
                "name" => "8-2.jpg"
                "alt" => null
                "width" => "2001"
                "height" => 2599
                "path" => "/media/geometrija_10/atanasjan-u23/1-eg-5/8-2.webp?ts=1739436213"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 939590
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1099}
            "task" => array:2 [
              "refs" => "745407"
              "type" => "task"
            ]
            "img" => array:2 [
              0 => array:5 [
                "name" => "8-1.jpg"
                "alt" => null
                "width" => "2001"
                "height" => 3253
                "path" => "/media/geometrija_10/atanasjan-u23/1-eg-5/8-1.webp?ts=1739436213"
              ]
              1 => array:5 [
                "name" => "8-2.jpg"
                "alt" => null
                "width" => "2001"
                "height" => 2599
                "path" => "/media/geometrija_10/atanasjan-u23/1-eg-5/8-2.webp?ts=1739436213"
              ]
            ]
          ]
          #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 {#1106
          #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" => 942953
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1034
              #items: array:1 [
                0 => App\Models\Edition {#1117
                  #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 {#1121 …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 {#1138 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1122 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1135 …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 {#1121 …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 {#1138 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1122 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1135 …2}
                    "field_content_source" => 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
            }
            "task" => array:2 [
              "refs" => "745407"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "8-1.png"
                "alt" => null
                "width" => "694"
                "height" => 5398
                "path" => "/media/geometrija_10/atanasjan-u23/2-eg-5/8-1.webp?ts=1739441835"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 942953
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1034}
            "task" => array:2 [
              "refs" => "745407"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "8-1.png"
                "alt" => null
                "width" => "694"
                "height" => 5398
                "path" => "/media/geometrija_10/atanasjan-u23/2-eg-5/8-1.webp?ts=1739441835"
              ]
            ]
          ]
          #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 {#1104
          #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" => 1352720
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1137
              #items: array:1 [
                0 => App\Models\Edition {#1139
                  #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" => 5120
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 6"
                    "field_order" => "7"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1144 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Gemini 2.5 Pro"
                    "field_moderator" => "vadim"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "6-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1148 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1141 …2}
                    "field_process_formula" => "katex"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1145 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 5120
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 6"
                    "field_order" => "7"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1144 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text"
                    "field_page_content_mode" => ""
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            "text" => "<p>Пусть в треугольнике $ABC$ даны углы $\angle A = 45^{\circ}$ и $\angle C = 60^{\circ}$. Сумма углов в треугольнике равна $180^{\circ}$, поэтому третий угол $\angle B = 180^{\circ} - \angle A - \angle C = 180^{\circ} - 45^{\circ} - 60^{\circ} = 75^{\circ}$.</p><p>Отрезки $AM$, $BN$ и $CK$ являются высотами треугольника, опущенными на стороны $BC$, $AC$ и $AB$ соответственно. Точки $M$, $N$, $K$ — основания этих высот. Требуется найти отношение длин отрезков $MN$ и $KN$.</p><p>Рассмотрим треугольник $AKN$. Так как $CK$ — высота, то $\triangle AKC$ — прямоугольный, и $AK = AC \cdot \cos(\angle A)$. Так как $BN$ — высота, то $\triangle ANB$ — прямоугольный, и $AN = AB \cdot \cos(\angle A)$.<br>В $\triangle AKN$ применим теорему косинусов для стороны $KN$:<br>$KN^2 = AK^2 + AN^2 - 2 \cdot AK \cdot AN \cdot \cos(\angle A)$<br>$KN^2 = (AC \cdot \cos(A))^2 + (AB \cdot \cos(A))^2 - 2 \cdot (AC \cdot \cos(A)) \cdot (AB \cdot \cos(A)) \cdot \cos(A)$<br>$KN^2 = \cos^2(A) \cdot (AC^2 + AB^2 - 2 \cdot AC \cdot AB \cdot \cos(A))$<br>Выражение в скобках по теореме косинусов для $\triangle ABC$ равно $BC^2$. Обозначим стороны $BC=a, AC=b, AB=c$. Тогда $b^2+c^2-2bc \cos(A) = a^2$.<br>$KN^2 = a^2 \cdot \cos^2(A) \Rightarrow KN = a \cdot |\cos(A)|$. Так как $\angle A = 45^{\circ}$ — острый, $KN = a \cdot \cos(A)$.</p><p>Аналогично рассмотрим треугольник $CMN$. Так как $AM$ — высота, то $\triangle AMC$ — прямоугольный, и $CM = AC \cdot \cos(\angle C)$. Так как $BN$ — высота, то $\triangle BNC$ — прямоугольный, и $CN = BC \cdot \cos(\angle C)$.<br>В $\triangle CMN$ применим теорему косинусов для стороны $MN$:<br>$MN^2 = CM^2 + CN^2 - 2 \cdot CM \cdot CN \cdot \cos(\angle C)$<br>$MN^2 = (AC \cdot \cos(C))^2 + (BC \cdot \cos(C))^2 - 2 \cdot (AC \cdot \cos(C)) \cdot (BC \cdot \cos(C)) \cdot \cos(C)$<br>$MN^2 = \cos^2(C) \cdot (AC^2 + BC^2 - 2 \cdot AC \cdot BC \cdot \cos(C))$<br>Выражение в скобках по теореме косинусов для $\triangle ABC$ равно $AB^2$. То есть $b^2+a^2-2ab \cos(C) = c^2$.<br>$MN^2 = c^2 \cdot \cos^2(C) \Rightarrow MN = c \cdot |\cos(C)|$. Так как $\angle C = 60^{\circ}$ — острый, $MN = c \cdot \cos(C)$.</p><p>Теперь найдем искомое отношение $\frac{MN}{KN}$:<br>$\frac{MN}{KN} = \frac{c \cdot \cos(C)}{a \cdot \cos(A)}$<br>По теореме синусов в $\triangle ABC$ имеем: $\frac{a}{\sin(A)} = \frac{c}{\sin(C)}$, откуда $\frac{c}{a} = \frac{\sin(C)}{\sin(A)}$.<br>Подставим это соотношение в нашу формулу: $\frac{MN}{KN} = \frac{\sin(C)}{\sin(A)} \cdot \frac{\cos(C)}{\cos(A)} = \frac{\sin(C)\cos(C)}{\sin(A)\cos(A)}$<br>Используя формулу синуса двойного угла $\sin(2\alpha) = 2\sin(\alpha)\cos(\alpha)$, получаем:<br>$\frac{MN}{KN} = \frac{\frac{1}{2}\sin(2C)}{\frac{1}{2}\sin(2A)} = \frac{\sin(2C)}{\sin(2A)}$</p><p>Подставим значения углов $A=45^{\circ}$ и $C=60^{\circ}$:<br>$\frac{MN}{KN} = \frac{\sin(2 \cdot 60^{\circ})}{\sin(2 \cdot 45^{\circ})} = \frac{\sin(120^{\circ})}{\sin(90^{\circ})}$<br>Так как $\sin(120^{\circ}) = \sin(180^{\circ} - 60^{\circ}) = \sin(60^{\circ}) = \frac{\sqrt{3}}{2}$ и $\sin(90^{\circ}) = 1$, то:<br>$\frac{MN}{KN} = \frac{\frac{\sqrt{3}}{2}}{1} = \frac{\sqrt{3}}{2}$</p><p>Ответ: $\frac{\sqrt{3}}{2}$</p>"
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            "text" => "<p>Пусть в треугольнике $ABC$ даны углы $\angle A = 45^{\circ}$ и $\angle C = 60^{\circ}$. Сумма углов в треугольнике равна $180^{\circ}$, поэтому третий угол $\angle B = 180^{\circ} - \angle A - \angle C = 180^{\circ} - 45^{\circ} - 60^{\circ} = 75^{\circ}$.</p><p>Отрезки $AM$, $BN$ и $CK$ являются высотами треугольника, опущенными на стороны $BC$, $AC$ и $AB$ соответственно. Точки $M$, $N$, $K$ — основания этих высот. Требуется найти отношение длин отрезков $MN$ и $KN$.</p><p>Рассмотрим треугольник $AKN$. Так как $CK$ — высота, то $\triangle AKC$ — прямоугольный, и $AK = AC \cdot \cos(\angle A)$. Так как $BN$ — высота, то $\triangle ANB$ — прямоугольный, и $AN = AB \cdot \cos(\angle A)$.<br>В $\triangle AKN$ применим теорему косинусов для стороны $KN$:<br>$KN^2 = AK^2 + AN^2 - 2 \cdot AK \cdot AN \cdot \cos(\angle A)$<br>$KN^2 = (AC \cdot \cos(A))^2 + (AB \cdot \cos(A))^2 - 2 \cdot (AC \cdot \cos(A)) \cdot (AB \cdot \cos(A)) \cdot \cos(A)$<br>$KN^2 = \cos^2(A) \cdot (AC^2 + AB^2 - 2 \cdot AC \cdot AB \cdot \cos(A))$<br>Выражение в скобках по теореме косинусов для $\triangle ABC$ равно $BC^2$. Обозначим стороны $BC=a, AC=b, AB=c$. Тогда $b^2+c^2-2bc \cos(A) = a^2$.<br>$KN^2 = a^2 \cdot \cos^2(A) \Rightarrow KN = a \cdot |\cos(A)|$. Так как $\angle A = 45^{\circ}$ — острый, $KN = a \cdot \cos(A)$.</p><p>Аналогично рассмотрим треугольник $CMN$. Так как $AM$ — высота, то $\triangle AMC$ — прямоугольный, и $CM = AC \cdot \cos(\angle C)$. Так как $BN$ — высота, то $\triangle BNC$ — прямоугольный, и $CN = BC \cdot \cos(\angle C)$.<br>В $\triangle CMN$ применим теорему косинусов для стороны $MN$:<br>$MN^2 = CM^2 + CN^2 - 2 \cdot CM \cdot CN \cdot \cos(\angle C)$<br>$MN^2 = (AC \cdot \cos(C))^2 + (BC \cdot \cos(C))^2 - 2 \cdot (AC \cdot \cos(C)) \cdot (BC \cdot \cos(C)) \cdot \cos(C)$<br>$MN^2 = \cos^2(C) \cdot (AC^2 + BC^2 - 2 \cdot AC \cdot BC \cdot \cos(C))$<br>Выражение в скобках по теореме косинусов для $\triangle ABC$ равно $AB^2$. То есть $b^2+a^2-2ab \cos(C) = c^2$.<br>$MN^2 = c^2 \cdot \cos^2(C) \Rightarrow MN = c \cdot |\cos(C)|$. Так как $\angle C = 60^{\circ}$ — острый, $MN = c \cdot \cos(C)$.</p><p>Теперь найдем искомое отношение $\frac{MN}{KN}$:<br>$\frac{MN}{KN} = \frac{c \cdot \cos(C)}{a \cdot \cos(A)}$<br>По теореме синусов в $\triangle ABC$ имеем: $\frac{a}{\sin(A)} = \frac{c}{\sin(C)}$, откуда $\frac{c}{a} = \frac{\sin(C)}{\sin(A)}$.<br>Подставим это соотношение в нашу формулу: $\frac{MN}{KN} = \frac{\sin(C)}{\sin(A)} \cdot \frac{\cos(C)}{\cos(A)} = \frac{\sin(C)\cos(C)}{\sin(A)\cos(A)}$<br>Используя формулу синуса двойного угла $\sin(2\alpha) = 2\sin(\alpha)\cos(\alpha)$, получаем:<br>$\frac{MN}{KN} = \frac{\frac{1}{2}\sin(2C)}{\frac{1}{2}\sin(2A)} = \frac{\sin(2C)}{\sin(2A)}$</p><p>Подставим значения углов $A=45^{\circ}$ и $C=60^{\circ}$:<br>$\frac{MN}{KN} = \frac{\sin(2 \cdot 60^{\circ})}{\sin(2 \cdot 45^{\circ})} = \frac{\sin(120^{\circ})}{\sin(90^{\circ})}$<br>Так как $\sin(120^{\circ}) = \sin(180^{\circ} - 60^{\circ}) = \sin(60^{\circ}) = \frac{\sqrt{3}}{2}$ и $\sin(90^{\circ}) = 1$, то:<br>$\frac{MN}{KN} = \frac{\frac{\sqrt{3}}{2}}{1} = \frac{\sqrt{3}}{2}$</p><p>Ответ: $\frac{\sqrt{3}}{2}$</p>"
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№8 (с. 237)
Условие. №8 (с. 237)
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 237, номер 8, Условие

8. Углы A и C треугольника ABC равны 45° и 60°. Отрезки AM, BN и CK — высоты треугольника. Найдите отношение MNKN.

Решение 1. №8 (с. 237)
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 237, номер 8, Решение 1
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 237, номер 8, Решение 1 (продолжение 2)
Решение 2. №8 (с. 237)
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 237, номер 8, Решение 2
Решение 6. №8 (с. 237)

Пусть в треугольнике $ABC$ даны углы $\angle A = 45^{\circ}$ и $\angle C = 60^{\circ}$. Сумма углов в треугольнике равна $180^{\circ}$, поэтому третий угол $\angle B = 180^{\circ} - \angle A - \angle C = 180^{\circ} - 45^{\circ} - 60^{\circ} = 75^{\circ}$.

Отрезки $AM$, $BN$ и $CK$ являются высотами треугольника, опущенными на стороны $BC$, $AC$ и $AB$ соответственно. Точки $M$, $N$, $K$ — основания этих высот. Требуется найти отношение длин отрезков $MN$ и $KN$.

Рассмотрим треугольник $AKN$. Так как $CK$ — высота, то $\triangle AKC$ — прямоугольный, и $AK = AC \cdot \cos(\angle A)$. Так как $BN$ — высота, то $\triangle ANB$ — прямоугольный, и $AN = AB \cdot \cos(\angle A)$.
В $\triangle AKN$ применим теорему косинусов для стороны $KN$:
$KN^2 = AK^2 + AN^2 - 2 \cdot AK \cdot AN \cdot \cos(\angle A)$
$KN^2 = (AC \cdot \cos(A))^2 + (AB \cdot \cos(A))^2 - 2 \cdot (AC \cdot \cos(A)) \cdot (AB \cdot \cos(A)) \cdot \cos(A)$
$KN^2 = \cos^2(A) \cdot (AC^2 + AB^2 - 2 \cdot AC \cdot AB \cdot \cos(A))$
Выражение в скобках по теореме косинусов для $\triangle ABC$ равно $BC^2$. Обозначим стороны $BC=a, AC=b, AB=c$. Тогда $b^2+c^2-2bc \cos(A) = a^2$.
$KN^2 = a^2 \cdot \cos^2(A) \Rightarrow KN = a \cdot |\cos(A)|$. Так как $\angle A = 45^{\circ}$ — острый, $KN = a \cdot \cos(A)$.

Аналогично рассмотрим треугольник $CMN$. Так как $AM$ — высота, то $\triangle AMC$ — прямоугольный, и $CM = AC \cdot \cos(\angle C)$. Так как $BN$ — высота, то $\triangle BNC$ — прямоугольный, и $CN = BC \cdot \cos(\angle C)$.
В $\triangle CMN$ применим теорему косинусов для стороны $MN$:
$MN^2 = CM^2 + CN^2 - 2 \cdot CM \cdot CN \cdot \cos(\angle C)$
$MN^2 = (AC \cdot \cos(C))^2 + (BC \cdot \cos(C))^2 - 2 \cdot (AC \cdot \cos(C)) \cdot (BC \cdot \cos(C)) \cdot \cos(C)$
$MN^2 = \cos^2(C) \cdot (AC^2 + BC^2 - 2 \cdot AC \cdot BC \cdot \cos(C))$
Выражение в скобках по теореме косинусов для $\triangle ABC$ равно $AB^2$. То есть $b^2+a^2-2ab \cos(C) = c^2$.
$MN^2 = c^2 \cdot \cos^2(C) \Rightarrow MN = c \cdot |\cos(C)|$. Так как $\angle C = 60^{\circ}$ — острый, $MN = c \cdot \cos(C)$.

Теперь найдем искомое отношение $\frac{MN}{KN}$:
$\frac{MN}{KN} = \frac{c \cdot \cos(C)}{a \cdot \cos(A)}$
По теореме синусов в $\triangle ABC$ имеем: $\frac{a}{\sin(A)} = \frac{c}{\sin(C)}$, откуда $\frac{c}{a} = \frac{\sin(C)}{\sin(A)}$.
Подставим это соотношение в нашу формулу: $\frac{MN}{KN} = \frac{\sin(C)}{\sin(A)} \cdot \frac{\cos(C)}{\cos(A)} = \frac{\sin(C)\cos(C)}{\sin(A)\cos(A)}$
Используя формулу синуса двойного угла $\sin(2\alpha) = 2\sin(\alpha)\cos(\alpha)$, получаем:
$\frac{MN}{KN} = \frac{\frac{1}{2}\sin(2C)}{\frac{1}{2}\sin(2A)} = \frac{\sin(2C)}{\sin(2A)}$

Подставим значения углов $A=45^{\circ}$ и $C=60^{\circ}$:
$\frac{MN}{KN} = \frac{\sin(2 \cdot 60^{\circ})}{\sin(2 \cdot 45^{\circ})} = \frac{\sin(120^{\circ})}{\sin(90^{\circ})}$
Так как $\sin(120^{\circ}) = \sin(180^{\circ} - 60^{\circ}) = \sin(60^{\circ}) = \frac{\sqrt{3}}{2}$ и $\sin(90^{\circ}) = 1$, то:
$\frac{MN}{KN} = \frac{\frac{\sqrt{3}}{2}}{1} = \frac{\sqrt{3}}{2}$

Ответ: $\frac{\sqrt{3}}{2}$

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