Parallel Lines in the Coordinate Plane

1
Section 3-6

• Parallel Lines in the Coordinate Plane

2
What is the slope of a line?

• The ratio of the vertical change (the rise) to
  the horizontal change (the run)

3
Slopes of Parallel Lines Postulate

• In a coordinate plane, two nonvertical lines are
  parallel if and only if they have the same slope.
  Any two vertical lines are parallel.

4
Slope Intercept Form
5
The y-intercept is the y-coordinate of the point
where the line crosses the y-axis.