Warm Up

1. Week 4 Warm Up 11.09.11 Describe what each acronym means: 1) AAA 2) AAS 3) SSA 4) ASA

2. Postulate 21 B E C F A D ∠A ≅∠D ≅ ∠C ≅∠F ∆ABC ≅ ∆DEF because of ASA.

3. Theorem 4.5 B E C F A D ≅ ∠C ≅∠F ∠A ≅∠D , and If , then ∆ABC ≅ ∆DEF because of AAS.

4. Ex 1 Prove Theorem 4.5: ∆ABC ≅ ∆DEF: B E C F A D ∠A ≅ ∠D Given ∠C ≅ ∠F Given Given ≅ Third Angle Theorem (4.3) ∠B ≅ ∠E ∆ABC ≅ ∆DEF ASA ( P21 )

5. Ex 2 Prove ∆EFG ≅ ∆JHG: E H G F J is given. ≅ ∠E ≅ ∠J is given ∠EGF ≅ ∠JGH are vertical angles. ∆EFG ≅ ∆JHG because of AAS.

6. Ex 3 Prove ∆ABD ≅ ∆EBC: C A B D ≅ E ∥ Given Given Alternate Interior Angles Theorem (3.8) ∠D ≅ ∠C ∠ABD ≅ ∠EBC Vertical Angles Theorem (2.6) ∆ABD ≅ ∆EBC ASA

7. Do: 1 Is ∆NQM ≅ ∆PMQ? Give congruency statements to prove it. Q N P M Assignment: Textbook Page 223, 8 - 22 all.