# Formative Assessment: Understanding Congruence

Grades 9-12 / Math / Geometry
CCSS: Math.HSG.CO.B.6 Math.HSG.CO.B.7 Math.HSG.CO.B.8

Common Core State Standards

 Math Math HSG High School: Geometry CO Congruence B Understand congruence in terms of rigid motions 6 Use geometric descriptions of rigid motions to transform figures and to predict the effect of a given rigid motion on a given figure; given two figures, use the definition of congruence in terms of rigid motions to decide if they are congruent. Download Common Core State Standards (PDF 1.2 MB)

Common Core State Standards

 Math Math HSG High School: Geometry CO Congruence B Understand congruence in terms of rigid motions 7 Use the definition of congruence in terms of rigid motions to show that two triangles are congruent if and only if corresponding pairs of sides and corresponding pairs of angles are congruent. Download Common Core State Standards (PDF 1.2 MB)

Common Core State Standards

 Math Math HSG High School: Geometry CO Congruence B Understand congruence in terms of rigid motions 8 Explain how the criteria for triangle congruence (ASA, SAS, and SSS) follow from the definition of congruence in terms of rigid motions. Download Common Core State Standards (PDF 1.2 MB)

### Lesson Objective

Formatively assess understanding of congruence in terms of rigid motions

15 minutes

### Questions to Consider

• Why does Ms. Pforts begin her class by asking students for real-world examples of congruent figures?
• Why does Ms. Pforts give the students graph paper and shapes in addition to the geometry software?
• How does Ms. Pforts know when students are ready to work on the extension activity?

Watch all the videos in this series: Formative Assessment Practices to Support Student Learning

Common Core Standards
Math.HSG.CO.B.6, Math.HSG.CO.B.7, Math.HSG.CO.B.8