Triangle Congruency Basics

Front

SSS (Side-Side-Side) Postulate

Back

three sides of one triangle are equal to three sides of another triangle, the triangles are congruent.

Front

SAS (Side-Angle-Side) Postulate

Back

two sides and the included angle of one triangle are equal to two sides and the included angle of another triangle, the triangles are congruent.

Front

ASA (Angle-Side-Angle) Postulate

Back

two angles and the included side of one triangle are equal to two angles and the included side of another triangle, the triangles are congruent.

Front

AAS (Angle-Angle-Side) Theorem

Back

two angles and a non-included side of one triangle are equal to two angles and the corresponding non-included side of another triangle, the triangles are congruent.

Front

RHS (Right angle-Hypotenuse-Side) Theorem

Back

right triangles, if the hypotenuse and one side are equal, the triangles are congruent.

Front

Congruent triangles example

Back

Front

Corresponding parts of congruent triangles

Back

sides and angles are equal in congruent triangles.

Front

Property: Area of congruent triangles

Back

triangles have equal areas.

Front

Property: Perimeter of congruent triangles

Back

triangles have equal perimeters.

Front

Non-congruence by AAA

Back

(Angle-Angle-Angle) does not guarantee triangle congruence, only similarity.