Для перевода градусов в радианы, нужно умножить градусную меру на $$\frac{\pi}{180}\$$.
a) 210°:
\[ 210° \cdot \frac{\pi}{180} = \frac{210\pi}{180} = \frac{7\pi}{6} \]
72°:
\[ 72° \cdot \frac{\pi}{180} = \frac{72\pi}{180} = \frac{2\pi}{5} \]
270°:
\[ 270° \cdot \frac{\pi}{180} = \frac{270\pi}{180} = \frac{3\pi}{2} \]
б) 315°:
\[ 315° \cdot \frac{\pi}{180} = \frac{315\pi}{180} = \frac{7\pi}{4} \]
60°:
\[ 60° \cdot \frac{\pi}{180} = \frac{60\pi}{180} = \frac{\pi}{3} \]
120°:
\[ 120° \cdot \frac{\pi}{180} = \frac{120\pi}{180} = \frac{2\pi}{3} \]
Ответ:
а) $$\frac{7\pi}{6}, \frac{2\pi}{5}, \frac{3\pi}{2}$$
б) $$\frac{7\pi}{4}, \frac{\pi}{3}, \frac{2\pi}{3}$$