
Equations of Parallel and Perpendicular Lines
Grade 9th Grade · Math · 60 min
What's Included
Learning Objective
I can write an equation for a parallel or perpendicular line given another line and a point
Warm-Up Video
Tyler Wallace · 5:00
Parallel and Perpendicular - Equations
Guided Notes
3 key concepts
- 1
Parallel lines have the same slope, while perpendicular lines have opposite reciprocal slopes.
- 2
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.
- 3
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
12 questions · Multiple choice & Short answer
Exit Ticket
Quick comprehension check
“Write the equation of a line that is perpendicular to the line y = -5x + 3 and passes through the point (5, -2).”
Teacher Guide
Get the complete package:
- Answer keys for all questions
- Differentiation strategies
- Extension activities
- Printable student handouts



