Найдите боковую сторону, если угол при вершине равнобедренного треугольника равен 120°, а - Дата: 01.11.2019, Автор: dustyhorton

Найдите боковую сторону, если угол при вершине равнобедренного треугольника равен 120°, а основание равно 42 см
- Предмет:
  Математика
- Автор:
  dustyhorton
- 6 лет назад

Ответы 1

Данный угол в 120° может лежать только против основания. Значит при основании углы по 30° (т.е. (180-120)/2=30). Опускаем высоту на основание, котора, являясь медианой, отсекает 21 см. Далее cos 30 как отношение 21 см к боковой стороне:cos 30° = 21/xx=21/cos30° = 21*2/√3=42*√3/3=14√3 - длина боковой стороны
- Автор:
  kyleeyd1k
- 6 лет назад
- 0
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Найдите боковую сторону, если угол при вершине равнобедренного треугольника равен 120°, а основание равно 42 см

Ответы 1

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