Parallel and Perpendicular Lines Calculator
Enter the slope of the given line and the point the new line passes through — you will get the parallel (same slope) or perpendicular (negative reciprocal) line equation with steps.
How to use
- Enter the slope and point, then select the relation.
- Special cases for perpendicular lines are also handled (horizontal/vertical, slope 0 or undefined).
Note: Parallel lines have equal slopes. The slopes of perpendicular lines multiply to −1, that is m₂ = −1/m₁.
Frequently Asked Questions (FAQ)
What does this calculator do?
Enter the slope of a given line and the point the new line passes through. It returns the parallel line equation (same slope) or the perpendicular line equation (negative reciprocal slope).
In what form is the answer shown?
The new line is shown in the form y = mx + c, where m is the slope and c is the y-intercept.
Does it show the steps?
Yes, a steps and breakdown section shows how the equation was derived.
What is the perpendicular slope rule?
The slope of a perpendicular line is the negative reciprocal of the original slope. If the given line has slope 2, the perpendicular line has slope -1/2.