Question

ndrew’s rotation maps point M(9, –1) to M’(–9, 1). Which describes the rotation?
180 degrees rotation
270 degrees clockwise rotation
90 degrees counterclockwise rotation
90 degrees clockwise rotation

Answer 1

180 degrees rotation.

A 180° rotation about the origin sends (x,y) to (−x,−y); (9, −1) → (−9, 1), which matches M → M'.