# Lesson 17

Working with Rigid Transformations

### Lesson Narrative

In previous grades, students describe a sequence of rigid transformations that exhibits the congruence between two figures. To prepare students for future congruence proofs, this lesson asks students to come up with a systematic, point-by-point sequence of transformations that will work to take any pair of congruent polygons onto one another. As the focus shifts to sequences of transformations between figures with more general characteristics rather than specific measurements, encourage students to explain how they know that their sequences will cause certain points or lines to coincide. When students consider how generalizable a strategy for defining sequences of rigid transformation is, they are looking for the structures of pairs of congruent figures (MP7).

### Learning Goals

Teacher Facing

• Compare and contrast (orally) diagrams of transformations.
• Comprehend that the notation $A'$ represents the image of point $A$.
• Explain (orally and in writing) a sequence of transformations that take given points to another set of points.

### Student Facing

• Let’s compare transformed figures.

### Student Facing

• I can describe a transformation that takes given points to another set of points.

Building On