\[1)\ \beta = 90{^\circ}:\]
\[\alpha = 180{^\circ} - 90{^\circ} = 90{^\circ};\]
\[S_{n} = (n - 2) \bullet 180{^\circ} = n \bullet 90{^\circ}\]
\[n - 2 = \frac{1}{2}\text{n\ \ \ }\]
\[\frac{1}{2}n = 2\ \ \]
\[n = 4\ стороны.\]
\[Ответ:\ \ 4.\]
\[2)\ \beta = 24{^\circ}:\]
\[\alpha = 180{^\circ} - 24{^\circ} = 156{^\circ};\]
\[S_{n} = (n - 2) \bullet 180{^\circ} = n \bullet 156{^\circ}\]
\[n - 2 = \frac{13}{15}\text{n\ \ }\]
\[\frac{2}{15}n = 2\ \ \]
\[n = 15\ сторон.\]
\[Ответ:\ \ 15.\]