Creating Geometry Proofs

10Math39 min

Learning Objective

I can construct a geometric proof using theorems and postulates.

Lesson Flow

Watch Video

6 min

Guided Notes

8 min

Key concepts students will learn:

  • Two triangles are said to be similar if they have the same shape but different sizes, and congruent if they are absolutely identical.

  • The Side-Side-Side theorem states that if all three sides of one triangle are identical to the corresponding sides of another triangle, the two triangles must be congruent.

  • The Angle-Side-Angle theorem states that if a side and the two adjacent angles are identical to those of another triangle, the two triangles must be congruent.

Practice

12 min

7 questions • Multiple choice & Short answer

Exit Ticket

5 min

Given ∆ABC and ∆XYZ, where AB ≅ XY, BC ≅ YZ, and CA ≅ ZX, prove that ∆ABC ≅ ∆XYZ. State the theorem that justifies your proof.

Teacher Guide

Get the complete package:

  • Answer keys for all questions
  • Differentiation strategies
  • Extension activities
  • Printable student handouts