1. 19 12 15 7 8 14 11 20

2. Parallel Lines and transversals

3. Corresponding Angles 1 2 3 4 5 6 7 8

4. Alternate Exterior Angles1 2 3 4 5 6 7 8

5. Alternate Interior Angles1 2 3 4 5 6 7 8

6. Same Side Interior Angles
If 2 ││ (parallel) lines are cut by a transversal, then the same side int ∠s R supplementary. 1 2 3 4 5 6 7 8

7. Ex. 1 Solve for x. x
60°

8. Ex. 2 Solve for x and y. x y
143°

9. Ex. 3 Solve for x and y. x
152° y

10. Ex. 4 Solve for x, y and z. x
24° y z

11. Warm Up
Find the missing angle measures.
m∠14
m∠7
m∠8
m∠12
m∠20 8 12 7 14
105° 20

12. Using Algebra with Parallel Lines

13. Ex. 1 Solve for x. 3x
60°

14. Ex. 2 Solve for x.
2x + 90
x + 30

15. Ex. 3 Solve for x and y. y
106° 2x

16. Ex. 4 Solve for y.
(y – 20)° y
70°