How it works
This parallel and perpendicular lines worksheet opens with 12 problems: three pairs of drawn lines to classify, three pairs given as equations, points or slopes, three slopes to find and three equations to write.
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Parallel and perpendicular worksheet, four tasks
Parallel or perpendicular, from a graph: two drawn lines; count rise and run, then mark parallel, perpendicular or neither. Parallel or perpendicular, without a graph: the same choice from two equations, four points or two slopes. Parallel and perpendicular slopes: a slopes of parallel and perpendicular lines worksheet, one line given and two slopes to write. Parallel or perpendicular line through a point: an equations of parallel and perpendicular lines worksheet, such as through (2, 6), parallel to y = 5x − 3.
The two slope rules
Parallel lines have the same slope. Perpendicular lines have slopes that multiply to −1, so each is the negative reciprocal of the other: 4 and −1/4.
- About a third of the pairs are neither, with slopes that look close, such as −1/5 and 1/5.
- For a parallel and perpendicular slopes worksheet with no graphs, light only the third task; 16 problems fit one page.
- Other forms too prints some lines as 3x + 2y = 4, so students solve for y before comparing.
Questions and answers
How do I get a parallel and perpendicular lines worksheet PDF?
Press Print and choose Save as PDF in your browser's print window. The opening sheet is one page of 12 problems, then the answer key, which gives both slopes for every pair and redraws each graph.
How do you tell if two lines are parallel, perpendicular or neither?
Find both slopes. Equal slopes with different y-intercepts mean parallel lines. Slopes whose product is −1, such as 2 and −1/2, mean perpendicular lines. Anything else is neither.
What is the slope of a line perpendicular to y = 3x + 1?
It is −1/3. Flip the slope 3 to get 1/3, then change its sign. A parallel line keeps the slope 3. The key prints both: parallel 3, perpendicular −1/3.
How do you write the equation of a parallel line through a point?
Keep the slope and solve for b. Through (2, 6), parallel to y = 5x − 3: 6 = 5 × 2 + b, so b = −4 and the line is y = 5x − 4.