Geometry parallel and perpendicular lines worksheet
Parallel lines have the same slope. Perpendicular ones have slopes that multiply to negative one, which means flipping the fraction and changing the sign.
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Sigma Prep · sigmaprep.io/worksheets Name Parallel and Perpendicular LinesDate Period Find the slope, or write the equation.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name Parallel and Perpendicular LinesAnswer keyVersion 1Date Period Find the slope, or write the equation.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
Find the slope of a line perpendicular to
- The slope is 3, which is 3 over 1.
- Flip it to 1 over 3.
- Change the sign.
The answer is .
Where students go wrong
Flipping without negating, or negating without flipping. Both are needed, and the check is that the two slopes multiply to exactly -1.
Also called negative reciprocal, slopes of parallel lines or perpendicular slope.
What you can put on this worksheet
- Slopes of parallel and perpendicular lines
- Find the slope of a line parallel to →
- The equation through a point, parallel or perpendicular
- Write the equation of the line through perpendicular to →