p.230-232;#10, 15-18 all, 28, 31, 33, 35, 36-40(e), 44-49 10) JK = √10, KL = √10, JL = √20, FG = √10, GH = √10, FH = √20, not congruent b/c corresponding sides not congruent 15) SSS or SAS 16) not possible 17) not possible 18) SSS 28) Jonathan; the measure of angle DEF is needed to use SAS. 31) C 33) ΔACB = ΔDCE 35) ΔLMP = ΔNPM 36) 78 37) 102 38) 68 39) 22 40) 59 44) BE 45) /CBD 46) /BDA 47) CD 48) /CAE 49) /DXE

Proving Congruence ASA, AAS The greatest mistake you can make in life is to be continually fearing you will make one. -- Elbert Hubbard Proving Congruence ASA, AAS Chapter 4 Section 5 Learning Goal: Proving congruent triangles by ASA, and AAS

Congruence of Triangles--ASA Notice the Corresponding Parts ∆RTW ∆CGH

Using ASA in proofs Given AB || CD, AD || BC Prove ∆ ADB ∆CBD 2. ABD CDB 2. Alt Interior Th. 3. CBD ADB 3. Alt Interior Th. 4. BD BD 4. Reflexive Property 5. ∆ABD ∆CBD 5. ASA

Congruence of Triangles -- AAS

Using AAS Given AB || CD, A B Prove: AC BD F E A B C D 1. AB || CD 2. Draw CF ḻ AB, DE ḻ AB 2. Distance betwen a point and a line 3. CF DE 3. Distance between 2 parallel lines 4. AFC, BED = 90° 4. Def. of Perpendicular Lines 5. AFC BED 5. Substitution 6. ∆AFC ∆BED 6. AAS 7. AC BD 7. CPCTC

Congruence Summary

Homework Triangle Congruence Worksheet