\[\boxed{\mathbf{365.ОК\ ГДЗ - домашка\ на}\ 5}\]
\[Формула\ суммы\ углов\ \]
\[выпуглого\ многоугольника:\]
\[(n - 2) \bullet 180{^\circ};\ \ \ \]
\[где\ n - количество\ углов.\]
\[Формула\ нахождения\ \]
\[количества\ углов:\]
\[dn = (n - 2) \bullet 180{^\circ};\ \]
\[где\ d - величина\ одного\ угла.\]
\[360{^\circ} = 180{^\circ}n - dn\]
\[n = \frac{360{^\circ}}{180{^\circ} - d}.\]
\[\textbf{а)}\ d = 90{^\circ}:\]
\[n = \frac{360{^\circ}}{180{^\circ} - 90{^\circ}} = 4.\]
\[\textbf{б)}\ d = 60{^\circ}:\]
\[n = \frac{360{^\circ}}{180{^\circ} - 60{^\circ}} = 3.\]
\[\textbf{в)}\ d = 120{^\circ}:\]
\[n = \frac{360{^\circ}}{180{^\circ} - 120{^\circ}} = 6.\]
\[\textbf{г)}\ d = 108{^\circ}:\]
\[n = \frac{360{^\circ}}{180{^\circ} - 108{^\circ}} = 5.\ \]