Question

Finding the Image Points for 90° Rotations
Triangle ABC has vertices A(–2, –3), B(–5, –3), and C(–4, –2). The triangle is rotated 90° counterclockwise around the origin.


What is the correct set of image points for triangle A’B’C’?
A’(3, 2), B’(3, 5), C’(2, 4)
A’(3, –2), B’(3, –5), C’(2, –4)
A’(–3, –2), B’(–3, –5), C’(–2, –4)
A’(–3, 2), B’(–3, 5), C’(–2, 4)

Answer 1

Rotation by 90° CCW about the origin sends (x,y) → (−y, x).

A(−2,−3) → (−(−3), −2) = (3, −2)
B(−5,−3) → (−(−3), −5) = (3, −5)
C(−4,−2) → (−(−2), −4) = (2, −4)

So the correct set is: A'(3, −2), B'(3, −5), C'(2, −4).