Question

What is the algebraic rule for a figure that is rotated 270° counterclockwise about the origin?

A.
RO,–270°(x, y) → (–y, x)
B.
RO,–270°(x, y) → (x, –y)
C.
RO,270°(x, y) → (–x, –y)
D.
RO,270°(x, y) → (y, –x)

Answer 1

Each quadrants' angle is 90 degrees.

Rotating (x, y) -270 degrees would move it from quadrant I to quadrant IV.

(x, y) = (+, +) = Quadrant I
(-x, y) = (-, +) = Quadrant II
(-x, -y) = (-, -) = Quadrant III
(x, -y) = (+, -) = Quadrant IV

Hope this helps.

Answer 2

Also, counterclockwise would be -270 degrees, so you can rule out C and D.