Chapter 4 - Section 4.1 - Angles and Radian Measure - Exercise Set - Page 532: 45

quadrant III

$\frac{-2\pi}{3}$ radians It is a negative angle and obtained by rotating the terminal side clockwise $\frac{2\pi}{3}$ = $\pi$ - $\frac{\pi}{3}$ radians. We use |$\frac{-2\pi}{3}$| or $\frac{2\pi}{3}$ to determine the rotation. So $\frac{2\pi}{3}$ radians lies in quadrant III. Find the attachment.