Unit 5: Congruence, Proof, and Construction


Throughout the unit, students explore rigid motions isometries (translations, reflections, and rotations) in order to develop an understanding about what it means for two objects to be congruent. They establish triangle congruence criteria, based on analyses of rigid motions and formal constructions. Students solve problems about triangles, quadrilaterals and other polygons. They apply reasoning to complete geometric constructions and explain why they work.



Developed By: Debbie Seldomridge & Cynthia Burke

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Pre-Unit Assessment

Lesson 1

Geometry Vocabulary

Lesson 2

Geometry Glossary

Lesson 3

An Introduction to Transformations

Lesson 4

Transformations Viewed Algebraically

Lesson 5

Properties Preserved by Translations

Lesson 6

Properties Preserved by Reflections

Lesson 7

Properties Preserved by Rotations

Lesson 8

Rigid versus Non-Rigid Motion

Lesson 9

Triangle Congruence Shortcuts

Lesson 10

Geometric Constructions (Part I)

Lesson 11

Geometric Constructions (Part 2)

Lesson 12

Geometric Constructions in a Circle

Lesson 13

Capstone Performance Task

Post-Unit Assessment