Congruent Triangles Module 5.2

Geometry module 5.2

Principle of superposition

Two figures are congruent if and only if there exists a rigid motion or series of rigid motions that maps one figure exactly onto another.

Congruent polygon

Polygons in which all matching parts are congruent

Corresponding parts

Matching parts of congruent polygons

Theorem 4.3 Third angles theorem

If two angles of one triangle are congruent to two angles of a second triangle, then the third angles of the triangles are congruent.

Theorem 4,4 Properties of Triangle Congruence

• Reflexive property of angle congruence: Triangle ABC is congruent to Triangle ABC

• Symmetric Property of Triangle Congruence: If triangle ABC is congruent to triangle to EFG then triangle EFG is congruent to triangle ABC.

• If triangle ABC is congruent EFG and triangle EFG is congruent to triangle JKL then triangle ABC is congruent to triangle JKL