Предмет: Геометрия, автор: daniilGlecov

помогите пожалуйста! даю 100 баллов

Приложения:

Simba2017: да, промахнулась я
Simba2017: AE=5V3; S=5V3*5/2=12.5V3
Simba2017: запутали меня!!
Simba2017: S=AE*EC=5V3*5=25V3-это окончательный ответ
Simba2017: AE=(AD+BC)/2
Аноним: Так я же треугольника.
Аноним: Может, я тоже промахнулась.
Simba2017: трапеции искали, но похоже зря..
Simba2017: если треугольника BCD -то не найти

Ответы

Автор ответа: Miroslava227
0

Ответ:

решение на фотографии.

Приложения:
Автор ответа: sergeybasso
1

Ответ:

25√3

Объяснение:

ΔAEC:

tg 30°=5/AE

AE=5/tg 30°=5/(1/√3)=5*√3

Площадь трапеции = произведение полусуммы оснований на высоту. Высота = 5. Полусумма оснований = (AD+BC)/2=(AE+ED+BC)/2=(2BC+2ED)/2=(BC+ED)=AE (видно, если опустить высоту из точки B).

Значит Площадь = 5*√3 *5=25√3


daniilGlecov: от души
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