1. Для \(216^\circ\): \(\frac{216 \times \pi}{180} = \frac{6\pi}{5}\) 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: \(\frac{6\pi}{5}\), \(\frac{\pi}{12}\), \(-\frac{\pi}{3}\)