Corresponding Parts of Congruent Triangles

Lesson 4-4

Review: Name the 5 triangle congruency theorems/postulates

• SSS

• SAS

• AAS

• ASA

• HL

Ways that DO NOT prove triangles are congruent

• AAA

• SSA

What can be done with congruent triangles?

• Triangles are congruent if all corresponding sides and angles are congruent.

• If we prove 2 triangles are congruent, we can state that any of their corresponding parts are congruent.

• This property is known as “Corresponding Parts of Congruent Triangles are Congruent” or CPCTC.

EX 1: Measuring Distance using CPCTC

EX 2:

EX 3: Prove angle C is congruent to angle E

A second look at ConstructionsThe construction of a perpendicular

bisector is shown below. How can

you prove that CP ┴ l ?

Homework

• Heading: 4-4 pg 262 # 1, 2, 4, 8, 9, 11, 15, 16, 17, 18, 20, 21

• Due Tuesday

* #8, 9 and 11 are the only problems you need to write a flowchart proof for.