1. p ;#10, 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) ) 68 39) 22
40) ) BE 45) /CBD 46) /BDA
47) CD 48) /CAE 49) /DXE

2. 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

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

4. 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

5. Congruence of Triangles -- AAS

6. 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

7. Congruence Summary

8. Homework
Triangle Congruence Worksheet