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

2. A building contractor has just assembled two massive triangular trusses to support the roof of a recreation hall. Before the crane hoists the them into place, the contractor needs to verify the two triangular trusses are identical. Must the contractor measure and compare all six parts of both triangles?

3. One? Two? Angle - Angle Angle - Side Side - Side What is the smallest number of parts needed? Angle Side No

4. Three Parts? Side-Angle-Side (SAS) Side-Side-Side (SSS) Side-Angle-Angle (SAA)Angle-Side-Angle (ASA) Side-Side-Angle (SSA)Angle-Angle-Angle (AAA)

5. Side-Side-Side (SSS)

6. Angles Included vs. Excluded

8. Side-Angle-Side (SAS) the triangles are congruent.

9. B A D T ∆BAD Side-Side-Angle (SSA) ∆BAT Congruencies that work: Side-Side-Side (SSS) Side-Angle-Side (SAS) p. 230: 1-3, 10, 11, 12, 14, 39-41, 45, 46