1. Parallel Lines & Angle Relationships
Unit Essential Question:
How do parallel and intersecting lines impact angle relationships?
Parallel Lines & Angle Relationships

2. Properties of Parallel Lines
Essential Question:
What are the angle relationships created by lines cut by a transversal?

3. Transversal & Angles

4. Identify the following:
Transversal
Same-Side Interior
Corresponding Angles
Alternate Exterior
Alternate Interior
Same-Side Exterior

5. What happens when Lines are Parallel?

6. Corresponding Angles Postulate
Do we all AGREE?

7. Can you Prove these?
Use the Corresponding Angles Postulate to prove the following:

8. Two-Column Proof
If P , then Q .

9. Proof of Alternate Interior Angles

10. More Theorems

11. If a Transversal Intersects Two Parallel Lines, then…
Corresponding Angles are Congruent
Alternate Interior Angles are Congruent
Same-Side Interior Angles are Supplementary
Alternate Exterior Angles are Congruent
Same-Side Exterior Angles are Supplementary

12. Finding Angle Measures

13. Finding Angle Measures
Find x and y.

14. Opening Thoughts:

15. Proving Lines Parallel
How do you Prove that Lines are Parallel?

16. Converse of Corresponding Angles
Do you believe it to be true?
Can you find any Counterexamples?

18. Parallel & Perpendicular Lines
Essential Question:
What are the relationships between parallel and perpendicular lines?

20. Triangle Angle Sum Essential Question:
How do you use Parallel Lines to show that a Triangle has 180 degrees?