1. Using Properties of Parallel Lines
Chapter 3 Section 3.5
Using Properties of Parallel Lines

2. Warm-Up

3. New Theorems
Theorem 3.11: If two lines are parallel to the same line then the lines are parallel to each other p q r
If p // r and r // q, then p // q

4. New Theorems
Theorem 3.12: In a plane, if two lines are perpendicular to the same line, then they are parallel to each other m n p
If m  p and n  p, then m // n

5. State the postulate or theorem that allows you to conclude a // b

6. State the postulate or theorem that allows you to conclude a // b

7. State the postulate or theorem that allows you to conclude a // b

8. Explain how you would show that a // b
Explain how you would show that a // b. State any postulates or theorems you would use.

9. Explain how you would show that a // b
Explain how you would show that a // b. State any postulates or theorems you would use.

10. Constructions We will come back to these at a later date
Construct a perpendicular thru a given point
Copy an angle
Construct a parallel thru a given point

11. Complete the Two Column Proof of Theorem 3.12