This document discusses congruence and properties of congruent triangles. It defines congruence as two figures having the same size and shape, with corresponding angles and sides being congruent. If two triangles are congruent, corresponding angles and sides are congruent. The Third Angle Theorem states that if two angles of one triangle are congruent to two angles of another, the third angles are also congruent. Properties of congruent triangles include: reflexive, symmetric, and transitive properties. Examples are provided to illustrate these concepts.