1. 4.3 Proving Triangles are Congruent:
SSS & SAS

2. But first a little warm up…

4. How much do you need to know?
To prove two triangles are exactly alike? (congruent)
If all 6 parts (3 corresponding sides and 3 corresponding angles) are congruent….that would do it.
Any “shortcuts”?

5. Postulate 19-Side Side Side (SSS) Congruence Postulate
If three sides of one triangle are congruent to three sides of another triangle
Then the two triangles are congrurent.
The remaining parts are congruent.

6. Postulate 20-Side-Angle-Side (SAS) Congruence Postulate
If two sides and the included angle of one triangle are congruent to two sides and and included angle of another triangle…
Then the triangles are congruent.

7. Use the diagram. Name the included angle between the pair of sides given.

8. For each pair of congruent triangles, name the pairs of corresponding sides.

9. Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence postulate you would use.

10. Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence postulate you would use.

11. Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence postulate you would use.

12. Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence postulate you would use.

13. Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence postulate you would use.

14. Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence postulate you would use.

15. Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence postulate you would use.

16. Are these triangles congruent?
By what rule?
Could you use the distance formula to verify your claim?