1. Geometry 4-6 CPCTC C – Corresponding P – Parts of C – Congruent
T – Triangles are
After you prove two triangles are congruent using
SSS, SAS, ASA, AAS, or HL
Then you can say that all of their unmarked sides and angles are also congruent by CPCTC.

2. Example
Determine if the two Δ’s are congruent. If they are, find the value of x. A U
3x-3 V C 24 T B
ΔABC ≅ ΔTVU by HL. So, AB ≅ TV by CPCTC. 3x – 3 = 24 and x = 9.

3. Example
Determine if the two Δ’s are congruent. If they are, find the value of x. 2x
3x - 4
You cannot use unmarked sides. So, there is not enough information to prove the two triangles are congruent.

4. Example Given: PR bisects QPS and QRS. Find the values of x and y.
125° 12
2y - 4
x - 5°
ΔPRS ≅ ΔPRQ by ASA. PQ ≅ PS by CPCTC. 2y – 4 = 12 so y = 8.
∠Q ≅ ∠S by CPCTC. x – 5 = 125 so x = 130.