Rotation Matrix
You are the matrix (0 -1) about the origin
(1 0)
You are the matrix (-1 0) about the origin
(0 -1)
You are the matrix (0 1) about the origin
(-1 0)
You are the matrix (0 -1) about the origin
(1 0)
You are the matrix (-1 0) about the origin
(0 -1)
You are the matrix (0 1) about the origin
(-1 0)