1. Для \(210^\circ\): \(\frac{210 \times \pi}{180} = \frac{7\pi}{6}\) радиан.
2. Для \(15^\circ\): \(\frac{15 \times \pi}{180} = \frac{\pi}{12}\) радиан.
3. Для \(-60^\circ\): \(\frac{-60 \times \pi}{180} = -\frac{\pi}{3}\) радиан.
Ответ: \(\frac{7\pi}{6}\), \(\frac{\pi}{12}\), \(-\frac{\pi}{3}\)