# Corresponding Parts of Congruent Triangles are Congruent

#### 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.