Question

Follow the guided instructions below to rotate the figure 270, degrees270
∘
counter-clockwise about the origin.

Answer 1

Rotation 270° counterclockwise about the origin sends each point (x,y) to (y, −x).

Why: the rotation matrix for 270° CCW is
[ [0, 1],
[−1, 0] ]
so (x',y') = (0·x + 1·y, −1·x + 0·y) = (y, −x).

How to apply:
1. Take each vertex (x,y) of your figure.
2. Replace it with (y, −x).
3. Plot the new vertices and join them in the same order to get the rotated figure.

Example:
- A(2,1) → A'(1,−2)
- B(−1,3) → B'(3,1)
- C(0,−2) → C'(−2,0)

(270° CCW is the same as 90° clockwise.)