1. 4-4 Using Congruent Triangles: CPCTC
Objective: use triangle congruence and CPCTC to prove that parts of two triangles are congruent

2. Once you know the triangles are congruent, what can be concluded about:

3. Even though those parts were not marked as congruent, once we know that the triangles are congruent we can state that their corresponding parts are congruent.
This is what is referred to as CPCTC, which stands for Corresponding Parts of Congruent Triangles are Congruent.

4. In proofs, you may be asked to prove that an angle of one triangle is congruent to a corresponding angle of a second triangle, or a side of one triangle is congruent to a corresponding side of a second triangle.
In order to this, you must first prove that the triangles are congruent, using any of the congruence postulates/theorems discussed in class.
After you prove the triangles are congruent, you can then state that a specific pair of sides or angles are congruent by CPCTC.