First, we need to make this angle positive. So we are going to add 360 degrees to -70 to determine the positive form of this angle
-70+360=290
Quadrant I: 0-90
Quadrant II: 90-180
Quadrant III: 180-270
Quadrant IV: 270-360.
This angle is in quadrant IV since 290 is between 270 and 360
Hope this helps