Rotation

Lesson Objectives

1. Develop the definition of a rotation using constructions.

2. Describe the properties of and write rules for rotations.

3. Determine the image or pre-image of a figure after a given rotation.

Rotations

A rotation is a rigid transformation that...

• turns every point of a preimage through...

• a specified angle and ...

• about a fixed point.

The fixed point is called the center of rotation. The amount of rotation is called the angle of rotation.

When working in the coordinate plane assume the center of rotation to be the origin unless told otherwise. Also, assume a positive angle of rotation turns the figure counterclockwise, and a negative angle turns the figure clockwise (unless told otherwise).