Answer
Quadrant III
Work Step by Step
$\frac{4\pi}{3}$ radians
It is a positive angle and obtained by rotating the terminal side counterclockwise $\frac{4\pi}{3}$ = $\pi$ + $\frac{\pi}{3}$ radians.
So $\frac{4\pi}{3}$ radians lies in quadrant III
Find the attachment.