Answer:
see attached
Step-by-step explanation:
Angles are normally positive measured counterclockwise from the +x axis. An angle of -90° is an angle 90° clockwise. The rotation will map 1st, 3rd, and 4th-quadrant points to the 4th, 2nd, and 3rd quadrants, respectively.
The square in the figure is centered on the (presumed) rotation center, so rotating it 90° does not change its appearance.
