Congruence

Congruence means that two mathematical shapes or figures are exactly the same in both size and shape. If you were to place one congruent shape directly over the other, they would match perfectly.

Example

Two triangles, $\triangle ABC$ and $\triangle DEF$, are congruent (written as $\triangle ABC \cong \triangle DEF$) if all their corresponding sides and corresponding angles are equal, such as under the Side-Side-Side (SSS) or Side-Angle-Side (SAS) criteria.

See Also

• Similarity
• Geometry