Parallel and Perpendicular Examples in Math

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Parallel and Perpendicular.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Math.

Concept Recap

Parallel lines never intersect and have matching direction; perpendicular lines intersect at right angles.

Parallel tracks run side by side; perpendicular streets form a plus sign.

Read the full concept explanation β†’

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Direction determines whether lines are parallel or perpendicular.

Common stuck point: Students often confuse 'not parallel' with 'perpendicular'β€”lines can be neither parallel nor perpendicular.

Sense of Study hint: Check angle or slope evidence rather than relying only on the drawing.

Worked Examples

Example 1

easy
Find the equation of the line through (3, -1) that is parallel to y = 2x + 5.

Solution

  1. 1
    Parallel lines have equal slopes. The slope of y = 2x + 5 is m = 2, so the new line also has m = 2.
  2. 2
    Use point-slope form: y - (-1) = 2(x - 3).
  3. 3
    Simplify: y + 1 = 2x - 6, so y = 2x - 7.

Answer

y = 2x - 7
Parallel lines never intersect because they have identical slopes. To find a parallel line through a specific point, keep the slope the same and use point-slope form to determine the new y-intercept.

Example 2

medium
Find the equation of the line through (4, 1) that is perpendicular to 3x - y = 6.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy
Are the lines y = -4x + 1 and y = \frac{1}{4}x - 3 parallel, perpendicular, or neither?

Example 2

medium
Line \ell passes through (0,3) and (6,0). Find the equation of the line perpendicular to \ell passing through the origin.

Background Knowledge

These ideas may be useful before you work through the harder examples.

angleslineslope in geometry