Slopes of Parallel and Perpendicular Lines
Grade 9th Grade · Math · 45 min
What's Included
Learning Objective
I can determine if two lines are parallel, perpendicular, or neither by analyzing their slopes.
Warm-Up Video
Kayla Jones · 5:24
Parallel and Perpendicular Lines
Guided Notes
3 key concepts
- 1
Parallel lines have the same slope but different y-intercepts, meaning they never intersect.
- 2
Perpendicular lines intersect at a 90° angle and have negative reciprocal slopes.
- 3
To find the negative reciprocal of a slope, flip the fraction and change the sign.
Practice Questions
10 questions · Multiple choice & Short answer
Exit Ticket
Quick comprehension check
“Line A has the equation y = 3x + 5. Line B has the equation y = -⅓x + 2. Are lines A and B parallel, perpendicular, or neither? Explain your answer.”
Complete Lesson Package
Get all 3 ready-to-use resources:
Teacher Guide
Student Doc
Slides
