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.
