Key Concepts: Proving Congruence — ASA, AAS

ASA (Angle-Side-Angle) Postulate

If two angles and the included side of one Triangle are congruent to two angles and the included side of another Triangle, the triangles are congruent.

AAS (Angle-Angle-Side) Theorem

If two angles and a non-included side of one Triangle are congruent to the corresponding parts of another Triangle, the triangles are congruent.

Summary of Congruence Methods

• ✅ SSS — 3 sides
• ✅ SAS — 2 sides + included Angle
• ✅ ASA — 2 angles + included side
• ✅ AAS — 2 angles + non-included side
• ❌ SSA — NOT valid
• ❌ AAA — NOT valid (proves similarity only)