Lesson 3:

Slopes of Lines

Slopes of Lines

Section 3.3

Virginia SOL Standard G.3.ab

The student will use pictorial representations, including computer software, constructions, and coordinate methods, to solve problems involving symmetry and transformation. This will include

a) investigating and using formulas for finding distance, midpoint, and slope;

b) applying slope to verify and determine whether lines are parallel or perpendicular;

New Definitions

Slope

Rate of Change

New Postulates

Postulate 3.2: Slopes of Parallel Lines

Postulate 3.3: Slopes of Perpendicular Lines

New Theorems

None Today

Lesson 3 Objectives

The student will be able to…

1.Find slopes of lines.

2.Use slope to identify parallel and perpendicular lines.

Warm Up

Pick a partner.

You have a job: make sure you are on task.

You have a second job: make sure your partner is on task (and awake).

For anyone off task, both partners will be held responsible.

Warm up

Do this on a clean page in your notes.

Warm up

Warm up

Warm up

Find the slope in three steps

Find the slope in three steps

Find the slope

Find the slope

Find the slope

Find the slope

Find the slope

Same Slope?

Positive or Negative?

Positive or Negative?

Positive or Negative?

Positive or Negative?

Positive or Negative?

Positive or Negative?

Positive or Negative?

Parallel Lines

Parallel lines have the same slope.

Perpendicular Lines

Perpendicular lines have slopes that are negative inverses:

Ex: 〖slope〗_(1 )=3/2

And 〖slope〗_(2 )=(-2)/3

Homework

p. 190-191 – #13-31 odd

p. 194 – #62- 65

DUE Wednesday 10/2

View the full PowerPoint for this lesson here: