Предмет: Геометрия, автор: mrhoran

1)Дан квадрат с диагональю 4 корень из 2. Найти стороны и s квадрата.
2) Дан прямоугольный треугольник DAC
угол DAC равен 30 градусам
AD равно 3 см
Угол D-прямой
Найти остальные стороны и s треугольника DAC

Приложения:

Ответы

Автор ответа: Prostodevochkalol

1. Расстояние между В и NP равно по теореме пифагора корень (64+36)=10. Это расстояние есть высота треугольника MDN, соответственно его площадь равна 10*12/2=60. Площадь его проекции есть четверть площади данного квадрата, то есть 12*12/4=36. Расстояние между прямыми OD и MN есть перпендикуляр между ними, то есть половина стороны квадрата =6.
2. Зная диагональ квадрата, найдем, что сторона равна 12. Двугранный угол измеряется своим линейным, которым является угол между стороной квадрата и диагональю боковой стороны. Найдем cos A=AD/AD1=12/8корней из 3=корень (3)/2. Угол равен 30 градусов
Держи)

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