Question

Write the coordinates of the vertices after a rotation 90°
counterclockwise around the origin.

Answer 1

see explanation

Explanation:

under a counterclockwise rotation about the origin of 90°

a point (x, y ) → (- y, x ) , then

C (1, 9 ) → C' (- 9, 1 )

D (4, 9 ) → D' (- 9, 4 )

E (0, 3 ) → E' (- 3, 0 )