Предмет: Геометрия, автор: Kristofa77

Помогите пожалуйста!апофема правильной четырехугольной пирамиды равна стороне основания .найти двугранный угол между противоположными боковыми гранями

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Автор ответа: oganesbagoyan

Пусть пирамида SABCD правильная , S вершина пирамиды  , SE и SF апофемы пирамиды противоположных граней , например SAB и SCD    <ESF ,будет линейный угол двугранного угла между боковыми гранями ( SAB и  SCD) .
В треугольнике   ESF SE =SF =EF =a  .   <ESF   = 60° .
ответ : 60°  .

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