Предмет: Математика, автор: borischik

Вычислите площадь трапеции ABCD с основаниями AD и BC, если AD = 27 см, BC = 13 см, CD = 10см, угол D = 30 градусов. СРОЧНО , расписанно !!!!

Ответы

Автор ответа: лиа32
0
проведем высоту CH. Рассмотрим треугольник chd. Так как угол D равен 30 градусов, а угол chd равен 90 градусов, отсюда следует что угол H C D равен 60 градусов. найдём высоту CH. Так как она находится напротив меньшего угла, значит равна половине гипотенузы, то есть 3,5 см. Теперь найдем площадь трапеции. 27 плюс 13 равно 40 делим 40 на 220 20 умножить на 3,5 получаем 70.
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