Well there are $2 \pi \approx 6.28$ radians in a full circle.
So each quadrant has $\frac{2 \pi}{4} = \frac{\pi}{2} \approx 1.57$ radians.
Let's divide $- \frac{7}{\frac{\pi}{2}} \approx - 4.45$ Quadrants, so it is all the way around the circle clockwise and then about half way through the IV Quadrant.