# Geometry/Congruent Triangles

< Geometry

## Methods of Determining Congruence[edit | edit source]

Two triangles are congruent if:

- each pair of corresponding sides is congruent
- two pairs of corresponding angles are congruent and a pair of corresponding sides are congruent
- two pairs of corresponding sides and the angles included between them are congruent

## Tips for Proofs[edit | edit source]

Commonly used prerequisite knowledge in determining the congruence of two triangles includes:

- by the reflexive property, a segment is congruent to itself
- vertical angles are congruent
- when parallel lines are cut by a transversal corresponding angles are congruent
- when parallel lines are cut by a transversal alternate interior angles are congruent
- midpoints and bisectors divide segments and angles into two congruent parts