Lesson 4-4 Proving Triangles Congruent-SSS and SAS

1. Lesson 4-4 Proving Triangles Congruent-SSS and SAS

2. Included angle-The Angle formed by two adjacent sides of a polygon. Vocabulary

3. Concept 1

4. ___ ___ ___ ___ Given: QU AD, QD  AU Use SSS to Prove Triangles Congruent Prove: ΔQUD ΔADU Example 1

5. Which information is missing from the flowproof?Given: AC ABD is the midpoint of BC.Prove: ΔADC  ΔADB ___ ___ ___ ___ A.AC  AC B.AB  AB C.AD  AD D.CB  BC ___ ___ ___ ___ ___ ___ Example 1 CYP

6. Concept 2

7. ENTOMOLOGY The wings of one type of moth form two triangles. Write a two-column proof to prove that ΔFEG ΔHIG if EI FH, and G is the midpoint of both EI and FH. Use SAS to Prove Triangles are Congruent Example 3

8. The two-column proof is shown to prove that ΔABG ΔCGB if ABG  CGB and AB  CG. Choose the best reason to fill in the blank. Proof: Statements Reasons 1. 1. Given 2. ? Property 2. 3. SSS 3.ΔABGΔCGB A. Reflexive B. Symmetric C. Transitive D. Substitution Example 3