1. Warm-Up  Find the measure of all angles possible. 112º138º 2. 1.

2. 2.6 Parallel Line Angles Objective Be able to understand the angles made by parallel lines.

3. Special Angles on Parallel Lines  Investigation 1) Angles on Parallel Lines  Step 1) Using a ruler, draw a pair of parallel lines on your paper.  Step 2) Draw a line that intersects both parallel lines (a transversal). Angles on Parallel Lines

4. Special Angles on Parallel Lines  Step 3) Label the Angles 1-8 12 4 3 56 7 8

5. Special Angles on Parallel Lines  Step 4) Place the patty paper over angles 1-4 and trace the intersecting lines and the four angles. 12 43

6. Special Angles on Parallel Lines  Step 5) Slide the patty paper down to angles 5-8. What do you notice? 12 43

7. Special Angles on Parallel Lines KeywordConjectureSketch Corresponding Corresponding Angles are ___________. Angles (CA) Alternate InteriorAlternate Interior angles are __________. Angles (AIA) Alternate ExteriorAlternate Exterior angles are _________. Angles (AEA) congruent 43 8 65 12 7 43 8 65 12 7 43 8 65 12 7

8. Special Angles on Parallel Lines KeywordConjectureSketch Consecutive Interior Same Side Interior Angles Angles are _______________. Consecutive ExteriorSame side exterior angles Angles are ______________. Parallel lines If two parallel lines are cut by a transversal, then Conjecturecorresponding angles are ____________, alternate interior angles are ______________, and alternate exterior angles are ________________. supplementary 43 8 65 12 7 43 8 65 12 7 congruent

9. Special Angles on Parallel Lines  If 2 lines are cut by a transversal to form pairs of congruent Corresponding Angles, congruent Alternate Interior Angles, congruent Alternate Exterior Angles, supplementary Consecutive interior angles, or supplementary exterior angles, then the lines are ________________. Converse of Parallel Lines Conjecture parallel

10. Converse lm n p 12 3 4 5 6 78 910 1112 1314 16 15

11. Summary  Name four sets of angles formed by two parallel lines cut by a transversal  Name one set of supplementary angles formed by two parallel lines cut by a transversal.

12. Classwork: page 130 #7 copy the picture q a c 169 64 k s d 108 g h j i f e b 61 t 75 m n p 79

13. Homework  Pg 129 #1-3, 9-15  Pg. 140 #26