## Precalculus (6th Edition) Blitzer

120°, $\frac{2\pi}{3}$ radians
To calculate how many degrees the minute hand of a clock moves, multiply the fraction of the revolution by 360°. $\frac{1}{3}$ * 360° = 120° To calculate how many radians the minute hand of a clock moves, multiply the fraction of the revolution by 2$\pi$. $\frac{1}{3}$ * 2$\pi$ = $\frac{2\pi}{3}$ radians