1. Proving Lines Parallel
3-3
Proving Lines Parallel

2. Proving Lines Parallel #1m n 4 1 2 3 8 7 6 5
Postulate

3. Proving Lines Parallel #2m n 1 3 4 2 8 7 6 5

4. 8 1 7 2 6 3 5 4 m n
Statements
Reasons 1. 2. 3. 4.

5. Proving Lines Parallel #3m n 4 1 2 3 8 7 6 5

6. 8 1 7 2 6 3 5 4 m n
Statements
Reasons 1. 2. 3. 4.

7. Proving Lines Parallel #4m n 4 1 2 3 8 7 6 5

8. 8 1 7 2 6 3 5 4 m n
Statements
Reasons 1. 2. 3. 4. 5. 6. 7. 8.

9. Proving Lines Parallel #5
In a plane, two lines perpendicular to the same line are parallel. m n
Theorem k

10. Proving Lines Parallel #6
Two lines parallel to a third line are parallel to each other. m n
Theorem k

11. Is a II b? Why or Why not? 1. a b
60º a b
60º 2.

12. What line segments are parallel? Why are they parallel?3.
56º
124º
53º A B C D 4. E F G H I J
24º
36º
22º
38º

13. What values for b would l II m?5. m
(b-5)º

14. 6. A B C
(3x+20)º
(2y-5)º
(x+50)º D E F

15. Homework Copy down (& learn) Theorems 3-8 & 3-9
(They weren’t covered in class today.)
Section 3.3 Written Exercises (p ) #1-23 (all)
(Note: Be sure that you copy down all figures onto your homework paper.)