1. Lines & Angles

2. Parallel Lines Coplanar lines that don’t intersect

4. Symbol for parallel

5. We most often show lines or segments are parallel by marking them with arrowheads.

6. Skew lines Lines that don’t intersect because they are in different planes

7. Parallel planes Planes that do not intersect

8. Transversal . A line that cuts across. other lines 
Transversal  A line that cuts across other lines  Intersects 2 or more coplanar lines

9. Transversals divide two lines into regions we call interior and exterior.

10. We often refer to specific types of angles formed by transversals.

11. Corresponding Angles . Same side of transversal 
Corresponding Angles  Same side of transversal  Corresponding positions (e.g.: above or below the lines)

12. Which pairs of angles are corresponding angles?

13. Which pairs of angles are corresponding angles

14. Alternate interior angles . Opposite sides of. transversal 
Alternate interior angles  Opposite sides of transversal  Between the lines

15. Which pairs of angles are alternate interior angles?

16. Which pairs of angles are alternate interior angles? 2 & 5 3 & 6

17. Same-Side Interior Angles (also called “consecutive interior angles”)  Same side of transversal  Between the lines

18. Which pairs of angles are same-side interior angles?

19. Which pairs of angles are same-side interior angles? 2 & 6 3 & 5

20. Alternate exterior angles . Opposite side of. transversal 
Alternate exterior angles  Opposite side of transversal  Outside the lines

21. Which pairs of angles are alternate exterior angles?

22. Which pairs of angles are alternate exterior angles? 1 & 7 4 & 8

23. Identify the pairs of special angles.

24. Remember

25. . Parallel lines . Skew lines . Parallel planes . Transversal 
 Parallel lines  Skew lines  Parallel planes  Transversal  Interior/Exterior  Corresponding s  Alternate interior s  Same-side interior s  Alternate exterior s