1. 6.3 Congruent Triangles: SSS and SAS
Learning Objective: to prove that triangles are congruent without proving that all 6 corresponding parts are congruent.
Warm-up (IN) K
4. Name the triangles that appear to be congruent in the figure.
As we go over the warm-up problems, I will ask the students to explain why they answer they way they did. 2 V 1 U R S T

2. Notes Side-Side-Side (SSS) Postulate -
Learning Objective: to prove that triangles are congruent without proving that all 6 corresponding parts are congruent
Notes
Side-Side-Side (SSS) Postulate -
If 3 sides of a triangle are congruent to 3 sides of another triangle, then the triangles are congruent A B C D E F
Essential Questions:
What is the SSS postulate?

3. EX 1 – C B Statements Reasons D A
Learning Objective: to prove that triangles are congruent without proving that all 6 corresponding parts are congruent
EX 1 – D C A B
Statements
Reasons
Essential Questions:
How can you prove 2 triangles are congruent using SSS?

4. Side-Angle-Side (SAS) Postulate -
Learning Objective: to prove that triangles are congruent without proving that all 6 corresponding parts are congruent
Side-Angle-Side (SAS) Postulate -
If 2 sides and the included angle of one triangle are congruent to 2 sides and the included angle of another triangle, then the triangles are congruent A B C D E F
Essential Questions:
What are the possible lengths of the 3rd side of a triangle?
CKC (Checking Key Concepts) – the students will answer some problems similar to the examples from the book on a separate paper. They will then switch papers, and grade each others papers, and I will record the score to verify that they understand the triangle inequality theorems.
If the students do not do well on the CKC, I will do an activity where they will use pieces of spaghetti to make different length segments and determine if they will form triangles. If this is the case, the rest of this lesson will be done on Monday.
To discover the piecewise function that represents the absolute value function, I will ask the students to use values of x to determine the domain.

5. O EX 2 – N P Q Statements Reasons
Learning Objective: to prove that triangles are congruent without proving that all 6 corresponding parts are congruent O
EX 2 – N P Q
Statements
Reasons
Essential Questions:
How can you prove 2 triangles are congruent using SSS?

6. Learning Objective: to prove that triangles are congruent without proving that all 6 corresponding parts are congruent
CKC p. 295– in your notes!!!
In the CKC, the students explain what information is missing to prove triangles congruent. They will also write their own proof and compare and contrast the SSS and SAS postulates.

7. Out – Describe the SSS and SAS postulates
Out – Describe the SSS and SAS postulates. How do they help you prove 2 triangles are congruent?
Summary – Today, I learned…
HW – p. 295 # 1-11, 20, 22
I will have the students do a Write/Pair/Share with the Out.