1. Lines and Angles

2. Parallel lines – Coplanar lines that do not intersect. Symbol: || G F

3. Parallel lines – Coplanar lines that do not intersect.
Symbol: || E A D H B C G F

4. Parallel lines – Coplanar lines that do not intersect.
Symbol: || E A D H B C G F

5. Skew lines – Lines that do not intersect and are not parallel because they are noncoplanar.G F

6. Skew lines – Lines that do not intersect and are not parallel because they are noncoplanar.G F

7. Skew lines – Lines that do not intersect and are not parallel because they are noncoplanar.G F

8. Parallel Planes – Planes that do not intersect.B C G F

9. Parallel Planes – Planes that do not intersect.B C G F

10. Transversal – A line that intersects two or more coplanar lines at distinct points.1 2 3 4 5 6 7 8 l m t
transversal

11. Angles 3, 4, 5, and 6 lie between lines l and m
Angles 3, 4, 5, and 6 lie between lines l and m. They are interior angles.
transversal

12. Angles 1, 2, 7, and 8 lie outside lines l and m
Angles 1, 2, 7, and 8 lie outside lines l and m. They are exterior angles.
transversal

13. Alternate Interior Angles
interior, nonadjacent, opposite sides of transversal 1 2 3 4 5 6 7 8 l m t
4 and 6
3 and 5

14. Alternate Exterior Angles
exterior, nonadjacent, opposite sides of transversal 1 2 3 4 5 6 7 8 l m t
1 and 7
2 and 8

15. Corresponding Angles 1 and 5 2 and 6 4 and 8 3 and 7
same side of transversal, corresponding positions at each vertex 1 2 3 4 5 6 7 8 l m t
1 and 5
2 and 6
4 and 8
3 and 7

16. Same Side Interior Angles (Consecutive Interior Angles)
interior, same side of transversal 1 2 3 4 5 6 7 8 l m t
4 and 5
3 and 6