1. Parallel Lines and Transversals Section 3-1

2.  2 lines that do not intersect are either parallel or skew.  Parallel lines ( lines) do not intersect and are coplanar.  Skew lines do not intersect and are not coplanar.

3.  Parallel planes ( planes) do not intersect. Plane X is parallel to plane Y  A line and a plane are parallel if they do not intersect. X Y H G D E A B C F plane Y

4.  A transversal is a line that intersects 2 or more coplanar lines in different points. 1 2 3 4 5 6 78 transversal interior exterior

5.  Alternate interior angles are 2 nonadjacent interior angles on opposite sides of the transversal. 1 2 34 5 6 78

6.  Consecutive interior angles are 2 interior angles on the same side of the transversal. 1 2 34 5 6 78

7.  Alternate exterior angles are 2 nonadjacent exterior angles on opposite sides of the transversal. 1 2 34 5 6 78

8.  Consecutive exterior angles are 2 exterior angles on the same side of the transversal. 1 2 34 5 6 78

9.  Corresponding angles are 2 angles in corresponding positions relative to the 2 lines. 1 2 34 5 6 78

10. Joke Time  What did E.T.’s Mom say when he got home?  Where on Earth have you been?

11. What happened when the pig pen broke? The pigs had to use a pencil.