4.4 Using Congruent Triangles CPCTC November 30, 2009
4.1 ­ 4.3 Quick Review:
1. Find a partner.
2. Take out one piece of paper to share.
3. Divide the paper into four even boxes.
4. Draw and label an example for each scenario below.
5. Trade with another group to check each others answers.
SSS
In each box, draw and label a pair of triangles that could be proven congruent ASA
by the given theorem.
SAS
AAS
Nov 26­7:46 PM
1
4.4 Using Congruent Triangles CPCTC November 30, 2009
Nov 30­9:27 AM
2
4.4 Using Congruent Triangles CPCTC November 30, 2009
4.4 Using Congruent Triangles: CPCTC
Objective: Use triangle congruence and CPCTC to prove that parts of two triangles are congruent.
Nov 25­12:05 PM
3
4.4 Using Congruent Triangles CPCTC November 30, 2009
Nov 25­12:06 PM
4
4.4 Using Congruent Triangles CPCTC November 30, 2009
Review: You can use three parts of triangles to show that triangles are congruent with SSS, SAS, ASA, and AAS.
Once you know triangles are congruent, you can make conclusions about the remaining parts because, by definition, corresponding parts of congruent triangles are congruent.
CPCTC
Nov 25­12:09 PM
5
4.4 Using Congruent Triangles CPCTC Statements
November 30, 2009
Reasons
Nov 25­12:09 PM
6
4.4 Using Congruent Triangles CPCTC November 30, 2009
Example:
Statements
Reasons
Nov 25­12:11 PM
7
4.4 Using Congruent Triangles CPCTC November 30, 2009
Proof
Nov 25­12:12 PM
8
4.4 Using Congruent Triangles CPCTC November 30, 2009
slide
slide
Nov 25­12:12 PM
9
4.4 Using Congruent Triangles CPCTC November 30, 2009
About how wide was the river if the officer stepped off 20 paces and each pace was about 2 1/2 feet long?
Nov 25­12:12 PM
10
4.4 Using Congruent Triangles CPCTC November 30, 2009
Homework: page 222
(1 ­ 8, 14, 26, 27)
Nov 25­12:24 PM
11