第11章 11.5

(1)

$\frac{\pi}{4} = \frac{\pi}{4} \cdot \frac{360°}{2\pi} = 45°$

(2)

$\frac{\pi}{6} = \frac{\pi}{6} \cdot \frac{360°}{2\pi} = 30°$

(3)

$\frac{5\pi}{3} = \frac{5\pi}{3} \cdot \frac{360°}{2\pi} = 300°$

(4)

$1.2\pi = 1.2\pi \cdot \frac{360°}{2\pi} = 216°$