Предмет: Геометрия, автор: blackknight234

В треугольнике АВС угол С=90 градусов, синус А=4/5, АС=9. Найдите АВ

Ответы

Автор ответа: пимочка

cos² α+sin²α=1
cosα=√1-sin²α=√1-(4/5)²=√1-16/25=√25/25 - 16/25 = √9/25 = 3/5
cosА=АС/АВ
3/5=9/АВ
3АВ=5*9
3АВ=45
АВ=45:3
Ав=15

Автор ответа: alistair528589

да это верно

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