This document discusses ways to prove that two lines are parallel using angles formed when the lines are cut by a transversal. It provides examples of using corresponding angles, alternate interior angles, alternate exterior angles, and same-side interior angles to show lines are parallel. It also contains practice problems asking students to identify if lines are parallel based on given angle information and to find values of variables that would make lines parallel.

1. Chapter 3Section 3.3 Proving Lines Are Parallel 9/21/2010 1 Clark - Ch 3.4

3. Corresponding Angle Converse

4. Alternate Interior angles are , then the lines are parallel

5. Alternate Interior Angle Converse.

6. Alternate Exterior angles are  , then the lines are parallel

7. Alternate Exterior Angle Converse

8. Same Side Interior angles are supplementary , then the lines are parallel

9. Same SideInterior Angle Converse9/21/2010 2 Clark - Ch 3.4

11. 1 and 56 are supplementary

13. Corresponding Angle Converse9/21/2010 3 Clark - Ch 3.4

15. 1 and 79 are congruent

16. Alt. Int. Angle Converse9/21/2010 4 Clark - Ch 3.4

19. 4x + 24 = 180

20. 4x = 156

21. x = 395

23. 60 = 3x

24. 20 = x9/21/2010 6 Clark - Ch 3.4

25. Give the Choice or Choices That Makes the Statement True If two lines are cut by a transversal so that alternate interior angles are ___________, then the lines are parallel. If two lines are cut by a transversal so that same side interior angles are ___________, then the lines are parallel. congruent supplementary 9/21/2010 7 Clark - Ch 3.4

26. Give the Choice or Choices That Makes the Statement True If two lines are cut by a transversal so that ___________________________ are congruent, then the lines are parallel. alt interior angles, alt exterior angles, corresponding angles 9/21/2010 8 Clark - Ch 3.4

27. Complete the Two Column Proof Given Corres. ’s Postulate Given Transitive Alt. Ext ’s Converse 9/21/2010 9 Clark - Ch 3.4

28. Write a two column proof Statements Reasons 1.Given 1.l // m, 1  2 2.1  3 2.Corres. ’s Postulate 3.Transitive 3.2  3 4.a // b 4. Corres. ’s Converse 9/21/2010 10 Clark - Ch 3.4

29. Homework Pg 153-156 10-28, 34, 35, 45-48 9/21/2010 11 Clark - Ch 3.4