Rotations Section 4 3 Rotations A Rotation is

Rotations Section 4. 3

Rotations A Rotation is a transformation where each point in a shape is rotated a certain number of degrees. We have two methods for doing rotations. The Rotating the Graph Method and Formula Method.

Rotating the Graph Method Step 1: Plot the Pre-Image if it’s not given to you. Step 2: Look at how much you’re told to rotate the image. If it’s -90°, do 1 quarter-turn counter-clockwise - 180°, do 2 quarter-turns counter-clockwise - 270°, do 3 quarter-turns counter-clockwise Step 3: Record the new points as your Image. Step 4: Put your paper back the way it was. Step 5: Plot your new points.

C’ B’ Image Pre-Image A(1, 1) Rotating the Graph 90° A’ A’(-1, 1) B(2, 3) B’(-3, 2) C(4, 1) C’(-1, 4)

Rotating the Graph 180° Image Pre-Image A’(1, -2) A(-1, 2) B(-3, 1) C(-3, 3) B’ B’(3, -1) C’(3, -3) A’ C’

Rotating the Graph 270° Image Pre-Image A(4, -2) A’(-2, -4) B(2, -1) B’(-1, -2) C(1, -4) C’ B’ A’ C’(-4, -1)

Practice Rotate the Graph 90° Pre-Image A(-3, -3) A’(3, -3) B(-5, -4) B’(4, -5) C’ C(-2, -5) A’ B’ C’(5, -2)

Rotation Symmetry We say that a shape has rotational symmetry if there’s a way to rotate the shape so it appears to not change. H Symmetry at: 180° W No Symmetry

What kind of Rotation Symmetry do these shapes have, if any? E D