1. Chapter 9 - Transformations

2. 90 degree rotation (x 1, y 1 ) 180 degree rotation (x 2, y 2 ) 270 degree rotation (x 3, y 3 )

3. 9.3 - Rotations (notation) Correct Notation = r (angle, point) {object} r (90 , O) ABCD This “rotates” the quadrilateral ABCD an angle of 90 degrees counter-clockwise around the origin. r (180 , O) ABCD This “rotates” the quadrilateral ABCD an angle of 180 degrees counter-clockwise around the origin.

4. Section 9.3 – Rotation Rules

6. Rotating an Object around the Origin r (90 ,O) ABC x y Scale is 1 by 1 A BC A’ B’ C’ r (180 ,O) ABC r (270 ,O) ABC A” B” C” A’’’B’’’ C’’’