Geometry · Triangles & Congruence

AAS Congruence

HSG-SRT.B.5

Definition

Triangles are congruent if two angles and a non-included side are equal.

Examples

  • Two angles and a side that is NOT between them, matched in both triangles, proves congruence by AAS.
  • Triangles with 30 and 70 degree angles and a matching non-included side are congruent by AAS.

Key rule

AAS uses a side that is not between the two given angles.

Memory hook

Angle, Angle, Side — the side sits outside the two angles.