Предмет: Геометрия, автор: Velvetka

Найдите угол DEF, если градусные меры дуг DE и EF равны 150° и 68° соответственно.
Нужно решить подробно.​

Приложения:

Ответы

Автор ответа: all1gat0r
4

Ответ:

71 градус

Объяснение:

Соединим точки D и F и рассмотрим полученный треугольник DEF:

углы EFD, EDF - вписанные, значит по св-ву вписанного угла:

EFD=1/2*ED=75 градусов

EDF=1/2*EF=34 градуса

по теореме о сумме углов треугольника::

DEF=180-75-34=71 градус

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