Вопрос школьника по предмету Геометрия
Высота равнобедренного треугольника ВК=10, АВ=ВС, угол В=120 градусам . Найдите сторону АВ.
Ответ учителя по предмету Геометрия
Дано: ABC-рівнобедренний трикутник
Кут B=120градусів
BK-10 см
Знайти:AB
Трикутник рівнобедренний, а це означає
кут А=кутові С=(180-120):2=30 градусів
Розглядаємо трикутник BKC
BK,KC-катети
BC-гіпотенуза
Катет,який лежить навпроти кута 30 градусів дорівнює половині гіпотенузи
Звідси маємо:
BC=2*BD=20 см
Відповідь: 20 см.
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2 м 60 см = мм
1 м 25 см = мм