#### What does CPCTC stand for?

Corresponding Parts of Congruent Triangles are Congruent

C: | Corresponding |

P: | Parts |

C: | Congruent |

T: | Triangles |

C: | Congruent |

#### Ok..but what does that mean?

It means that if two trangles are known to be congruent , then all corresponding angles/sides are also congruent.

As an example, if 2 triangles are congruent by SSS, then we also know that the angles of 2 triangles are congruent.

**Practice** Proofs

##### Practice 1

**Prove** KJ $$ \cong $$ JI

##### Practice 2

**Prove** ML $$ \cong $$ MN

##### Practice 3

The proof below uses CPCTC to prove that the diagonals of a rhombus bisect the shape's angles. This proof relies upon CPCTC.

**All that is necessary for this proof is the following definition for a rhombus: a parallelogram with four congruent sides.**