Geometry · Triangles & Congruence
SAS Congruence
HSG-SRT.B.5
Definition
Triangles are congruent if two sides and the angle between them are equal.
Examples
- Two sides and the included angle matching proves triangles congruent by SAS.
- Triangles with sides 5 and 7 and an included 40 degree angle, matched in both triangles, are congruent by SAS.
Key rule
The angle in SAS must be the included angle — the one between the two given sides.
Memory hook
Side, Angle, Side — the angle must be sandwiched between the sides.