\[\boxed{\mathbf{341.}ОК\ ГДЗ\ –\ домашка\ на\ 5}\]
\[Дано:\]
\[S_{осн} = S = \pi R^{2};\]
\[h - высота\ цилиндра.\]
\[Решение.\]
\[В\ треугольнике\ AA_{1}B_{1}:\]
\[\frac{2R}{h} = tg\varphi;\ \ R = \sqrt{\frac{S}{\pi}};\ \ \]
\[h = \frac{2R}{\text{tgφ}} = ctg\varphi \cdot 2\sqrt{\frac{S}{\pi}}.\]
\[S_{бок} = 2\pi Rh =\]
\[= 2\pi\sqrt{\frac{S}{\pi}} \cdot ctg\varphi \cdot 2\pi\sqrt{\frac{S}{\pi}} =\]
\[= 4\pi \cdot ctg\varphi \cdot \frac{S}{\pi} = 4Sctg\varphi.\]
\[Ответ:\ 4Sctg\varphi.\]