Algebra II Workbook - Wayne County Public Schools

LESSON
2.2
NAME _________________________________________________________ DATE ____________
Practice with Examples
For use with pages 75–81
GOAL
Find slopes of lines, classify parallel and perpendicular lines, and use slope
to solve real-life problems
VOCABULARY
The slope of a nonvertical line is the ratio of the vertical change (the
rise) to the horizontal change (the run).
Two lines in a plane are parallel if they do not intersect and they have
the same slope.
Two lines in a plane are perpendicular if they intersect to form a right
angle. The slopes of two perpendicular lines are negative reciprocals.
EXAMPLE 1
Finding the Slope of a Line
Find the slope of the line passing through 1, 4 and 3, 4.
SOLUTION
Let x 1 , y 1 1, 4 and x 2 , y 2 3, 4.
m y 2 y 1
x 2 x 1
4 4
3 1
0
2
Write formula for slope.
Substitute values.
Simplify.
(3, 4) (1, 4)
1
y
1
x
Chapter 2
Because the slope is zero, the line is horizontal.
Exercises for Example 1
Find the slope of the line passing through the given points.
Then tell whether the line rises, falls, is horizontal, or is
vertical.
1. 3, 2, 5, 4
2. 4, 1, 6, 3
3. 2, 5, 7, 5
4. 5, 1, 5, 6
5. 4, 1, 4, 4
6. 2, 5, 2, 1
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Algebra 2 25
Practice Workbook with Examples