Two triangles are congruent triangles if their vertices can be paired so that corresponding sides are congruent and corresponding angles are congruent.
An included side is the side common to two angles of a triangle.
An included angle is the angle between the two sides of a triangle.
SSS (Side-Side-Side) Congruence Postulate
If three sides of one triangle are congruent to three sides of another triangle, then the triangles are congruent.
SAS (Side-Angle-Side) Congruence Postulate
If two sides and an included angle of one triangle are congruent to the corresponding two sides and included angle of another triangle, then the triangles are congruent.
ASA (Angle-Side-Angle) Congruence Postulate
If two angles and an included side of one triangle are congruent to the corresponding two angles and included side of another triangle, then the triangles are congruent.
AAS (Angle-Angle-Side) Congruence Theorem
If two angles and a non-included side of one triangle are congruent to the corresponding two angles and a non-included side of another triangle, then the triangles are congruent.
