1. 3.1 Lines and Angles

2. Parallel Lines

3. Skew Lines

4. Parallel Planes

6. Line t is a transversal here. Lines l and m are not transversals.
Transversal - A line that intersects two or more coplanar lines at distinct (different) points.
Line t is a transversal here. Lines l and m are not transversals.
Angles 3, 4, 5, 6 are referred to as INTERIOR ANGLES because they are between or on the inside of lines l and m.
Angles 1, 2, 8, 7 are referred to as EXTERIOR ANGLES because they are on the outsides of lines l and m.

11. HWK MathXL 3.1