1. Perpendicular and Parallel Lines

2. Computer:
Go to the computer and find the definition of parallel and perpendicular lines
One partner looks for the definition and one partner writes the definition down.

3. Class definition
Parallel lines: Perpendicular lines:

6. Computer: (switch researcher)
How do you know that two lines are parallel?
How do you know that two lines are perpendicular?

7. Notation
Parallel lines: Perpendicular lines:

8. Proofing How do you know that two lines are parallel?
You look at the slope in order to determine if two lines are parallel. If two lines have the SAME SLOPE, then they are parallel to each other.
𝑚= 𝑟𝑖𝑠𝑒 𝑟𝑢𝑛

9. Proofing 2) How do you know that two lines are perpendicular?
Look at the slope in order to determine if two lines are perpendicular
If two lines are negative reciprocal of each other, then they are perpendicular to each other.
If one slope is undefined (vertical line) and the other slope is zero (horizontal line), then they are perpendicular.

10. My Geometric House Examples