1. Для \(72^\circ\): \(\frac{72 \times \pi}{180} = \frac{2\pi}{5}\) радиан.
2. Для \(108^\circ\): \(\frac{108 \times \pi}{180} = \frac{3\pi}{5}\) радиан.
3. Для \(-270^\circ\): \(\frac{-270 \times \pi}{180} = -\frac{3\pi}{2}\) радиан.
Ответ: \(\frac{2\pi}{5}\), \(\frac{3\pi}{5}\), \(-\frac{3\pi}{2}\)