3.4 – Find and Use Slopes of Lines
The slope of a nonvertical line is the ratio of
vertical change (rise) to horizontal change
(run) between any two points on the line.
m = y2 – y1
x2 – x1
3.4 – Find and Use Slopes of Lines
3.4 – Find and Use Slopes of Lines
Example 1:
Find the slopes of line a and line d.
3.4 – Find and Use Slopes of Lines
Example 2:
Find the slopes of line b and line c.
3.4 – Find and Use Slopes of Lines
Comparing Slopes
When two lines intersect in a coordinate
plane, the steeper line has the slope with
greater absolute value. You can also
compare slopes to tell whether two lines are
parallel or perpendicular.
3.4 – Find and Use Slopes of Lines
3.4 – Find and Use Slopes of Lines
Example 3:
Find the slope of each line. Which lines are
parallel?
3.4 – Find and Use Slopes of Lines
Example 4:
Line h passes through (3, 0) and (7, 6). Graph
the line perpendicular to h that passes through
the point (2, 5).
3.4 – Find and Use Slopes of Lines
Example 5:
Determine which of the two lines is steeper.
Line 1: (-2, 3)(3, 5)
Line 2: (3, 1) (6, 5)
Line 1: (-2, -1)(1, -2)
Line 2: (-5, -3)(-1, -4)
3.4 – Find and Use Slopes of Lines
Example 6:
Determine if the two lines are parallel,
perpendicular, or intersecting.
Line 1: (1, 0)(7, 4)
Line 2: (7, 0) (3, 6)
Line 1: (-3, 1)(-7, -2)
Line 2: (2, -1)(8, 4)
3.4 – Find and Use Slopes of Lines
Example 7: