Equations of Parallel and Perpendicular Lines
Learning Objective
I can write an equation for a parallel or perpendicular line given another line and a point
Key Concepts
Parallel lines have the same slope, while perpendicular lines have opposite reciprocal slopes.
The point-slope equation, which is y - y₁ = m(x - x₁), can be used to find the equation of a line if you know the slope and a point on the line.
To find the equation of a parallel or perpendicular line, first identify the slope of the given line, then determine the slope of YOUR line. (Remember: you will need the SAME slope for parallel lines and the opposite reciprocal slope for perpendicular lines). Finally, use the point-slope equation to find the new equation.
Practice Questions
This lesson includes 12 practice questions to reinforce learning.
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1. What is the relationship between the slopes of parallel lines?
2. What is the relationship between the slopes of perpendicular lines?
3. Line A has the equation y = 3x + 2. What is the slope of any line parallel to Line A?
...and 9 more questions
Educational Video
Parallel and Perpendicular - Equations
Tyler Wallace