Answer
-4 radians.
Work Step by Step
Clockwise rotation -> negative angle
Draw a circular arc from the extremity of the initial side to the extremity of the terminal side. Use the formula:
$s=r\theta$
$\theta=\frac{s}{r}$
Given that the length of the arc, $s$, is about 4 times the length of the sides, $r$:
$\theta=-4~radians$
