Answer
$\frac{2\pi}{3}radians$
Work Step by Step
In order to convert degree measures to radians, we must multiply the given degree measure by $\frac{\pi}{180}$ and simplify.
$120^{\circ}=120\times(\frac{\pi}{180}radians)=\frac{120\pi}{180}radians=\frac{2\pi}{3}radians$
