All Intermediate Geometry Resources
Example Questions
Example Question #8 : How To Find Out If Lines Are Perpendicular
Are the lines of the equations
and
parallel, perpendicular, or neither?
Perpendicular
Parallel
Neither
Neither
Write each equation in the slope-intercept form by solving for ; the -coefficient is the slope of the line.
Subtract from both sides:
The line of this equation has slope .
Subtract from both sides:
Multiply both sides by
The line of this equation has slope .
Two lines are parallel if and only if they have the same slope; this is not the case. They are perpendicular if and only if the product of their slopes is ; this is not the case, since
.
The correct response is that the lines are neither parallel nor perpendicular.
Example Question #2 : How To Find Out If Lines Are Perpendicular
Are the lines of the equations
and
parallel, perpendicular, or neither?
Neither
Parallel
Perpendicular
Neither
Write each equation in the slope-intercept form by solving for ; the -coefficient is the slope of the line.
Subtract from both sides:
Multiply both sides by :
The slope is the -coefficient
Add to both sides:
Multiply both sides by :
The slope is the -coefficient .
Two lines are parallel if and only if they have the same slope; this is not the case. They are perpendicular if and only if the product of their slopes is ; this is not the case, since . The lines are neither parallel nor perpendicular.
Example Question #1 : How To Find Out If Lines Are Perpendicular
The slopes of two lines on the coordinate plane are and 4.
True or false: the lines are perpendicular.
True
False
True
Two lines on the coordinate plane are perpendicular if and only if the product of their slopes is . The product of the slopes of the lines in question is
,
so the lines are indeed perpendicular.
Example Question #11 : How To Find Out If Lines Are Perpendicular
Two lines intersect at the point . One line passes through the point ; the other passes through .
True or false: The lines are perpendicular.
True
False
False
Two lines are perpendicular if and only if the product of their slopes is . The slope of each line can be found from the coordinates of two points using the slope formula
To find the slope of the first line, set :
To find the slope of the second line, set :
The product of the slopes is
As the product is not , the lines are not perpendicular.
Example Question #171 : Lines
The slopes of two lines are 6 and . True or false: the lines are perpendicular.
False
True
False
Two lines on the coordinate plane are perpendicular if and only if the product of their slopes is . The product of the slopes of the lines in question is
The product is not equal to , so the lines are not perpendicular.