1. Warm Up 9/20/12  Solve for x and y 1.2.

2. Practice from Yesterday  k || m  If m  2 = 3x – 7 and m  5 = 2x + 4, find x and m  6 1 2 3 4 5 6 8 7 j k m

3.  Yesterday we learned about the Corresponding Angles Postulate  Who can remind the class what that is  “If a transversal intersects two parallel lines, then corresponding angles are congruent.”  What would the converse of this statement be?

4. Converse of the Corr. Angles Post.  Postulate 3-2  “If two lines and a transversal form corresponding angles that are congruent, then the two lines are parallel.

5. Converse of the Alternate Interior Angles Theorem  Postulate 3-3  “If two lines and a transversal form alternate interior angles that are congruent, then the two lines are parallel.

6. Converse of the Same-Side Interior Angles Theorem  Postulate 3-4  “If two lines and a transversal form same-side interior angles that are supplementary, then the two lines are parallel.

7. Review  We’ve now learned six theorems and postulates in this unit.  Talk to your partner to see if you can recall what the six theorems and postulates say.  Sketch a picture of each

8. Flow Charts!  Yesterday we saw two-column proofs in action. (Wasn’t it great?!)  Another form of proof is called the flow proof.  In this form, arrows show the logical connection between the statements.  Reasons are written below the statements.

9. Example

10. ff Which Lines, if any, must be parallel if angle 3 and 4 are congruent?

11. Relating Parallel and Perpendicular Lines ff

12. Using Algebra

13. Classwork  Practice 3-2  #1-7

14. Homework  Finish Practice 3-2  “3-4 Practice”