1. 4-2 Triangle Congruence by SSS and SAS
Objective: to prove two triangles congruent using the SSS and SAS Postulates

2. Remember: 4.1 Triangle Congruence
If you know 3 pairs of Corresponding Angles are congruent and 3 pairs of Corresponding Sides are Congruent, you knew that the triangles were congruent.

4. Side Side Side Postulate
All we need is to show 3 pairs of Corresponding Sides are congruent in order to prove Triangle Congruence.
Let’s look at a couple of two-column proofs that utilize the SSS Postulate.

5. Ex 1:Using SSS

6. Ex 1B:Try Another Proof!

7. Included
What does it mean to be included? Like you were included in an event or batteries are included?
The word Included can also used when referring to the sides and angles of a Triangle.

8. SAS Postulate

9. Ex 2: Using SAS

10. Ex 2B: Using SAS

11. Ex 3: Are the Triangles Congruent?

12. Ex 3B: Are the Triangles Congruent?

13. Apply: Are these Triangles Congruent?
If congruent say why, if not explain what else you would need to know to prove them congruent by SSS or SAS.

14. Apply: Are these Triangles Congruent?
If congruent say why, if not explain what else you would need to know to prove them congruent by SSS or SAS.

15. Practice Proofs!

16. More Proofs!