Question

Triangle PQR is shown on a coordinate plane.

Triangle P-Q-R is shown on a coordinate plane with vertex P located at coordinates (negative 1, 7), vertex Q located at (4, 3), and vertex R located at (3, negative 3).

Triangle PQR is rotated 90 degrees counterclockwise about the origin. At what coordinates are the vertices of the image of the triangle located?

Radio button to select the answer below
A.
,
,


Radio button to select the answer below
B.
,
,


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C.
,
,


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D.
,
,

Answer 1

Use the rule for a 90° counterclockwise rotation about the origin: (x,y) → (−y,x).

P(−1,7) → P'(−7,−1)
Q(4,3) → Q'(−3,4)
R(3,−3) → R'(3,3)

So the image vertices are (−7, −1), (−3, 4), and (3, 3).