Dynamic Activity

Rotations, Reflections, and Translations

Lesson Vocabulary

• rotation
• center of rotation
• angle of rotation
• center of a regular polygon

Take Note Key Concept: Rotation About a Point

A rotation of x ° x degrees  about a point R, called the center of rotation, is a transformation with these two properties:

• The image of R is itself (that is, R ′ = R r prime , equals r ).
• For any other point V, R V ′ = R V r v prime . equals r v  and m ∠ V R V ′ = x . m angle , v r v , prime equals x .

Image Long Description

The positive number of degrees a figure rotates is the angle of rotation.

A rotation about a point is an isometry.