1. Для \(252^\circ\): \(\frac{252 \times \pi}{180} = \frac{7\pi}{5}\) радиан.
2. Для \(45^\circ\): \(\frac{45 \times \pi}{180} = \frac{\pi}{4}\) радиан.
3. Для \(-240^\circ\): \(\frac{-240 \times \pi}{180} = -\frac{4\pi}{3}\) радиан.
Ответ: \(\frac{7\pi}{5}\), \(\frac{\pi}{4}\), \(-\frac{4\pi}{3}\)