counterclockwise rotation about the origin of 270°
the coordinates of Q(6, 2), R(4, 9), S(2, 7)
the coordinates of Q'(2, - 6), R'(9, - 4), S'(7, - 2)
Note that the x-coordinate of the image is the y-coordinate of the original and the y-coordinate of the image is the negative of the x-coordinate of the original
This is a counterclockwise rotation about the origin of 270°
a point (x, y) → (y, - x) ← in general
