1. Proving Triangles are Congruent
Section 4.2 & 4.3

2. Side-Side-Side (SSS) Congruence Postulate
If 3 sides of a triangle are congruent to 3 sides of another triangle, then the 2 triangles are congruent.

3. Are the following congruent?

4. Side-Angle-Side (SAS) Congruence Postulate
If 2 sides and the included angle of one triangle are congruent to the 2 sides and the included angle of a second triangle, then the 2 triangles are congruent.

5. Are the following congruent?

6. Angle-Side-Angle (ASA) Congruence Postulate
If 2 angles and the included side of a triangle are congruent to 2 angles and the included side of another triangle, then the 2 triangles are congruent.

7. Angle-Angle-Side (AAS) Congruence Postulate
If 2 angles and a nonincluded side of 1 triangle are congruent to 2 angles and the nonincluded side of another triangle, then the 2 triangles are congruent.

8. Are the following congruent?

9. Are the following congruent?

10. Hypotenuse Leg (HL)
If the hypotenuse and leg of one right triangle are congruent to the hypotenuse and leg in another right triangle, then the two triangles are congruent.

11. One type that doesn’t work.
AAA

12. Counterexample of AAA

13. The second type that doesn’t work.
ASS

14. Counterexample of ASS

15. Are the following congruent?

16. Are the following congruent?

17. Are the following congruent?

18. Are the following congruent?