Question

Triangle ABC has its vertices at the following coordinates:

A (-3Ė2) B (0Ė4) C (-10Ė6)
Give the coordinates of the image triangle A'B'C' after a 90° counterclockwise
rotation about the origin.

Answer 1

A' (- 2, - 3 ) , B' (- 4, 0 ) , C' (- 6, - 10 )

Explanation:

under a counterclockwise rotation about the origin of 90°

a point (x, y ) → (- y, x ) , then

A (- 3, 2 ) → A' (- 2, - 3 )

B (0, 4 ) → B' (- 4, 0 )

C (- 10, 6 ) → C' (- 6, - 10 )