\[\boxed{\mathbf{68.}\mathbf{ОК\ ГДЗ - домашка\ на}\ 5}\]
\[\mathbf{Работа\ по\ рисунку\ 48.}\]
\[\mathbf{Дано:}\]
\[\angle AOB = 50{^\circ}\]
\[\angle\text{FOE} = 70{^\circ}\]
\[\mathbf{Найти:}\]
\[\angle AOC;\ \ \ \angle BOD;\ \ \angle COE;\ \ \ \angle COD.\]
\[\mathbf{Решение.}\]
\[Углы\ BOC\ и\ FOE\ являются\ \]
\[вертикальными:\]
\[\angle BOC = \angle FOE = 70{^\circ}.\]
\[\angle COD =\]
\[= 180 - \angle COB - \angle AOB =\]
\[= 180{^\circ} - 70{^\circ} - 50{^\circ} = 60{^\circ}.\]
\[\angle AOC = \angle AOB + \angle BOC =\]
\[= 50{^\circ} + 70{^\circ} = 120{^\circ}.\]
\[\angle BOD = \angle BOC + \angle COD =\]
\[= 70{^\circ} + 60{^\circ} = 130{^\circ}.\]
\[Углы\ EOD\ и\ AOB\ являются\ \]
\[вертикальными:\]
\[\angle EOD = \angle AOB = 50{^\circ}.\]
\[\angle COE = \angle COD + \angle EOD =\]
\[= 60{^\circ} + 50{^\circ} = 110{^\circ}.\]
\[Ответ:\ \angle AOC = 120{^\circ};\]
\[\angle BOD = 130{^\circ};\ \]
\[\angle COE = 110{^\circ};\angle COD = 60{^\circ}.\]