\[R = 6\ см;\ \ \ a = 1\ ч:\]
\[1)\ a = 360{^\circ} \bullet \frac{1}{12} = 30{^\circ}.\]
\[2)\ L = \frac{\pi\text{Ra}}{180{^\circ}} = \frac{\pi \bullet 6 \bullet 30{^\circ}}{180{^\circ}} = \pi.\]
\[Ответ:\ \ \text{π\ }см.\]