2. Section 3.1 Lines and Angles 6/30/2016

3. Goals 1. Identify relationships between lines 2. Identify angles formed by transversals

4. Lines in the same plane that never intersect. AB and CD are parallel lines Parallel lines A B C D

5. Planes that never intersect. Planes U and W are parallel Parallel Planes wu

6. Skew Lines Noncoplanar lines. AB and CD are skew lines. C D A B

7. Transversal A line that intersects two or more coplanar lines at different points. m n l l is a transversal

8. Corresponding Angles Angles that occupy a similar position when two lines are cut by a transversal. 1 2  1 and  2 are corresponding angles

9. Alternate Exterior Angles Angles who lie on the outside the two lines on opposite sides of the transversal. 3 4  3 and  4 are alternate exterior angles

10. Alternate Interior Angles Two angles who lie between the two lines on opposite sides of the transversal 5 6  5 and  6 are alternate interior angles

11. Two angles that lie between the lines on the same side of the transversal Same-Side Interior Angles 7 8  7 and  8 are consecutive interior angles

12. Postulate 13 Parallel Postulate If there is a line and a point not on the line, then there is exactly one line through the point parallel to the given line P

13. Perpendicular Postulate If there is a line and a point not on the line, then there is exactly one line through the given point perpendicular to the given line. Postulate 14 P

14. Example #1 Which line… a.is parallel to and contains V? b.is perpendicular to and contains V? c.is skew to and contains V? T P Q R V W U S

15. Example #2 List all pairs of angles that fit the description. A Corresponding B Alternate Exterior C.Alternate Interior D.Consecutive Interior 6 51 2 3 4 7 8

16. Homework #12 Pages 148 #1-13