Rules for rotating points about the origin 1. The point (a,b) rotated 90° counterclockwise about the origin becomes (-b,a). 2. The point (a,b) rotated 180° counterclockwise about the origin becomes (-a,-a). 3. The point (a,b) rotated 270° counterclockwise (or 90° clockwise) about the origin becomes (b,-a). We use rule 1: A(-4,2) becomes A'(-2,-4) B(1,3) becomes B'(-3,1) C(-2,1) becomes C'(-1,-2) D(-3,-2) becomes D'(2,-3) The green polygon below rotated 90° counterclockwise about the origin becomes the red polygon:Edwin