Question

Triangle RST has vertices R(2, 0), S(4, 0), and T(1, –3). The image of triangle RST after a rotation has vertices
R'(0, –2), S'(0, –4), and T'(–3, –1). Which rule describes the transformation?

R0, 90°
R0, 180°
R0, 270°
R0, 360°

Answer 1

Rotation by 270° about the origin (equivalently 90° clockwise).

Reason: A 270° CCW rotation sends (x,y) to (y, −x). Applying that:
R(2,0) -> (0,−2), S(4,0) -> (0,−4), T(1,−3) -> (−3,−1),
which matches R', S', T'.