Algebra 1 : Perpendicular Lines
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Example Questions
Example Question #1 : Perpendicular Lines
Which ONE of these statements about the lines defined by the following equations is TRUE?
Line 1:
Line 2:
The lines intersect at the point 
The slopes of the two lines are identical.
The lines do not intersect.
The lines intersect and are perpendicular.
The lines intersect only once because they are parallel.
The lines intersect and are perpendicular.
The TRUE statement:
"The lines intersect and are perpendicular." This is true because the slopes of the two lines are opposite-reciprocals of each other.
The FALSE statements:
"The lines intersect at the point 
"The slopes of the two lines are identical." This is not true because the slope of Line 1 is 
"The lines do not intersect." The lines would need to be parallel (i.e., have the same slope) for this to be the case, but the lines do not have the same slope.
"The lines intersect only once because they are parallel." Parallel lines never intersect, so this statement cannot be made of any set of two lines.
Example Question #2 : Perpendicular Lines
Determine if the lines 
The lines are perpendicular
There is not enough information to determine the answer
The lines are not perpendicular
The lines are perpendicular
For lines to be perpendicular, the slopes need to be negative reciprocals of each other. For the line 
Example Question #3 : Perpendicular Lines
Which of these lines is perpendicular to
None of the other answers
Perpendicular lines have slopes that are negative reciprocals of each other. If you convert the given line to the 
which indicates a slope of 
Example Question #4 : Perpendicular Lines
Which of the following equations describes a line perpendicular to the line 
The line 
The equation 
The lines 
Example Question #5 : Perpendicular Lines
Which of these lines is perpendicular to 
Perpendicular lines have slopes that are negative reciprocals of one another. Since all of these lines are in the 
The slope of the original line is 
The only line with a slope of 
Example Question #6 : Perpendicular Lines
Which of the following lines could be perpendicular to the following:
None of the available answers
The only marker for whether lines are perpendicular is whether their slopes are the opposite-reciprocal for the other line's slope. The 
Example Question #5 : Perpendicular Lines
Find a line perpendicular to the line with the equation:
Lines can be written in the slope-intercept format:
In this format, 
In the given equation:
Perpendicular lines have slopes that are negative reciprocals of each other.
First, we need to find its reciprocal.
Second, we need to rewrite it with the opposite sign.
Only one of the choices has a slope of 
Example Question #6 : Perpendicular Lines
Find a line perpendicular to the line with the equation:
Lines can be written in the slope-intercept format:
In this format,
In the given equation:
Perpendicular lines have slopes that are negative reciprocals of each other.
First, we need to find its reciprocal.
Second, we need to rewrite it with the opposite sign.
Only one of the choices has a slope of 
Example Question #1 : How To Find Out If Lines Are Perpendicular
Find a line perpendicular to the line with the equation:
Lines can be written in the slope-intercept format:
In this format,
In the given equation:
Perpendicular lines have slopes that are negative reciprocals of each other.
First, we need to find its reciprocal.
Rewrite.
Second, we need to rewrite it with the opposite sign.
Only one of the choices has a slope of 
Example Question #10 : Perpendicular Lines
Find a line perpendicular to the line with the equation:
Lines can be written in the slope-intercept format:
In this format,
In the given equation:
Perpendicular lines have slopes that are negative reciprocals of each other.
First, we need to find its reciprocal.
Rewrite.
Second, we need to rewrite it with the opposite sign.
Only one of the choices has a slope of 
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