5.4ASA and AAS Congruence
Quick Answer
ASA: two angles and the included side. AAS: two angles and a non-included side. Both prove triangle congruence. The key difference is whether the side is between the two angles (ASA) or not (AAS).
Essential Question
How do ASA and AAS differ, and how do we decide which one applies to a given pair of triangles?
Learning Goals
- 1State the ASA Congruence Postulate and AAS Congruence Theorem.
- 2Identify the included side between two angles.
- 3Distinguish ASA from AAS in diagrams.
- 4Write two-column proofs using ASA and AAS.
Key Vocabulary
ASA Congruence Postulate
If two angles and the included side of one triangle are congruent to those of another, the triangles are congruent.
AAS Congruence Theorem
If two angles and a non-included side of one triangle are congruent to those of another, the triangles are congruent.
Included side
The side between two given angles of a triangle.
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.