Lesson objective: Practice describing transformations in the coordinate plane.

This lesson helps to build fluency with describing transformations in the coordinate plane. Polygons in the coordinate plane are used here because they clearly demonstrate the transformations that figures undergo in the plane. This work develops students' understanding that the structure of the coordinate plane allows us to describe geometric transformations using coordinates.

Students engage in Mathematical Practice 6 (attend to precision) as they choose the proper details for descriptions of transformations in the coordinate plane. Prompts give students little more instruction than "Describe the transformation," but this is because students are responsible for knowing which details are necessary and for providing those specific details.

**Key vocabulary:**

- center of rotation
- line of reflection
- reflect
- rotate
- translate

**Special materials needed:**

- patty paper (optional)
- transparency and wet or dry-erase marker (optional alternative to patty paper)