Решебник по геометрии 8 класс Мерзляк Задание 283

\[1)\ \angle BAC = 40{^\circ}:\]

\[\angle BDC = \angle BAC = \frac{1}{2}\angle BOC;\]

\[\angle BDC = \angle BAC = 40{^\circ}.\]

\[Ответ:\ \ 40{^\circ}.\]

\[2)\ \angle BOC = 70{^\circ}:\]

\[\angle BEC = \frac{1}{2}\angle BOC = 35{^\circ}.\]

\[Ответ:\ \ 35{^\circ}.\]

\[3)\ \angle CDE = 80{^\circ}:\]

\[\cup CE = \angle COE = 2\angle CDE;\]

\[\cup CE = 2\angle CDE = 160{^\circ}.\]

\[Ответ:\ \ 160{^\circ}.\]

\[4)\ \cup DBA = 300{^\circ}:\]

\[\angle DBA = \frac{1}{2}\angle DOA = \frac{1}{2} \cup DA;\]

\[\cup DA = 360{^\circ} - \ \cup DBA = 60{^\circ};\]

\[\angle DBA = \frac{1}{2} \bullet 60{^\circ} = 30{^\circ}.\]

\[Овет:\ \ 30{^\circ}.\]