1. 3.1 and 3.2 Parallel lines and transversals
Chapter 3
3.1 and 3.2
Parallel lines and transversals

2. Parallel Lines
Parallel lines are coplanar lines that do not intersect.
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3. Skew Lines
Skew lines are lines that are non-coplanar and do not intersect. Ex: What lines are skew to ?

4. Parallel Planes
Parallel planes are planes that do not intersect. Ex : Name a set of parallel planes.

5. Example 1 – do not need to copy problem for notes

6. Transversal
Transversal - A line that intersects two or more lines in a plane at different points. t m n

7. When the transversal intersects two lines, eight angles are formed, which have special names.

8. Alternate Interior Angles-
Nonadjacent interior angles that lie on opposite sides of the transversal.

9. Alternate Exterior Angles- nonadjacent exterior angles that lie on opposite sides of the transversal.
Angles 1 and Angles 2 and 8

10. Corresponding Angles – lie on the same side of the transversal and in corresponding positions.

11. Same Side Interior Angles – interior angles that lie on the same side of the transversal.

12. Take out worksheet pages 59, 63, 67, 87
#1-12, 14,16-24, 27

13. Additional Problems

14. 3-1 Corresponding angles postulate
If two parallel lines are cut by a transversal, then corresponding angles are congruent.
 2   6,  1   5,  3   7,  4   8 1 2 3 4 5 6 7 8
Lesson 2-4: Angles and Parallel Lines

15. 3-2 Same Side Interior Angles Theorem (or Consecutive angles theorem)
If two parallel lines are cut by a transversal, then then each pair of same side interior angles is supplementary.
m3 +m5 = 180º, m4 +m6 = 180º 1 2 3 4 5 6 7 8
Lesson 2-4: Angles and Parallel Lines

16. Lesson 2-4: Angles and Parallel Lines
Alternate Angles
3-1 Alternate Interior Angles Thereom: If two parallel lines are cut by a transversal, then each pair of alternate interior angles are Congruent.
3-3 Alternate Exterior Angles: If two parallel lines are cut by a transversal, then each pair of alternate exterior angles are Congruent.
 3   6,  4   5
 2   7,  1   8 1 2 3 4 5 6 7 8
Lesson 2-4: Angles and Parallel Lines

18. Worksheet , 14, 15, 16

19. Homework
Pg , 37-42
Pg , 12-20, 22, 23-24