Unit 4 · Triangle Foundations

4.5Congruent Figures and Corresponding Parts

Quick Answer

Two figures are congruent if all corresponding sides and angles are congruent. The order of vertices in a congruence statement (△ABC ≅ △DEF) tells you which parts correspond: A↔D, B↔E, C↔F.

Essential Question

What does it mean for two figures to be congruent, and how does the order of vertices in a congruence statement communicate which parts correspond?

Learning Goals

  • 1Define congruent figures.
  • 2Identify corresponding sides and angles from a congruence statement.
  • 3Write a congruence statement in correct vertex order.
  • 4Use congruence marks to identify corresponding parts in a diagram.

Key Vocabulary

Congruent figures

Figures in which all corresponding sides and angles are congruent.

Corresponding parts

Matching sides and angles of congruent figures.

Congruence statement

A statement such as △ABC ≅ △DEF that identifies corresponding vertices in order.

Full lesson content coming soon

Worked examples, guided practice problems, a workbook, quiz, and downloadable PDF resources will be added to this lesson in Phase 2. The learning goals and vocabulary above reflect the complete lesson scope.