Exploring CPCTC and Congruent Triangles

In this lesson, Justin introduces CPCTC, an acronym for 'corresponding parts of congruent triangles are congruent.' The video explains how CPCTC is used to identify congruent parts of triangles once their congruence is established. The lesson outlines the steps to apply CPCTC in proofs, including using triangle congruence theorems and writing congruent statements. An example problem is provided to illustrate the application of CPCTC, followed by a practice question to reinforce learning. The video emphasizes the importance of understanding CPCTC for upcoming units on proofs.

What does CPCTC stand for?

• Congruent polygons of corresponding triangles

• Corresponding polygons of congruent triangles

• Corresponding parts of congruent triangles are congruent

• Congruent parts of corresponding triangles are congruent

Which theorem was used as an example to show triangle congruence?

• SSS

• ASA

• HL

• SAS

What is the first step in the process of stating congruences using CPCTC?

• State that the triangles are congruent using a theorem

• Write a congruent statement

• Use CPCTC to state all other congruences

• Identify corresponding parts of the triangles

How many total congruences are there within two congruent triangles?

• Five

• Six

• Four

• Seven

What must be done before using CPCTC?

• Draw the triangles on a coordinate plane

• Prove that the triangles are congruent

• Measure all sides of the triangles

• Identify all angles as congruent

Which of the following is NOT a step in using CPCTC?

• Using CPCTC to state congruences not given

• Writing a congruent statement

• Stating that all sides are equal in length

• Proving the triangles are congruent

What is the final step in the process of using CPCTC?

• Writing a congruent statement

• Proving the triangles are congruent

• Identifying corresponding parts of the triangles

• Using CPCTC to state all other congruences

Why is it important to write the matching vertices in the same location in a congruent statement?

• To identify the corresponding sides and angles

• To simplify the calculation of area

• To make the diagram look cleaner

• To ensure the triangles are similar

What does CPCTC allow us to state?

• The method to prove triangles congruent

• The congruence of polygons

• The congruence of circles

• Congruences that weren't initially given

In the example problem, what was the correct congruency statement allowed by CPCTC?

• Triangle CGE is congruent to Triangle DLM

• Segment CG is congruent to Segment DL

• Angles G and L are congruent

• Angle C is congruent to angle M