Question

which rotation may have occurred?
○ a 45° rotation clockwise
○ a 45° rotation counterclockwise
○ a 90° rotation clockwise
○ a 90° rotation counterclockwise

Explanation:

First, identify a reference point, such as point $N(0,0)$ (the origin, which maps to itself). Then look at point $M$: original $M$ is at $(2,6)$, rotated $M'$ is at $(6,-2)$. Using the rotation rule for 90° clockwise rotation: a point $(x,y)$ becomes $(y,-x)$. Substituting $x=2, y=6$ gives $(6,-2)$, which matches $M'$. Checking other points confirms this rule applies, and the shape does not show a 45° rotation (which would not align with grid axes cleanly).

Answer:

a 90° rotation clockwise