Parallel and perpendicular lines - Definition with Examples

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Parallel and Perpendicular Lines

Two lines in a plane either meet on extending or do not meet at all.


Parallel lines

Lines in a plane that never meet, even if we extend them, are called parallel lines. As they never meet, the distance between the parallel lines remains constant.

For instance:

Example 1: In the given picture, the rails of the railroad track represent parallel lines as the distance between the rails remains the same.

Parallel Lines

Example 2: Lines of a writing pad are another example of parallel lines. 

Parellel Lined Notebook

Example 3: In the given picture parking line stripes show parallel lines.

Parallel Parking

Intersecting lines

Lines which meet or appear to meet when extended are called intersecting lines and the point where they meet is called the point of intersection.


Perpendicular lines

Lines which meet (intersect) each other at right angles are called perpendicular lines. In geometry, perpendicular lines are represented using the symbol ‘’.

For instance:

Example 1: The given picture shows the perpendicular lines in the floor tiles.

Intersecting Lines

Example 2: In the given picture, the vertical and the horizontal lines (black and pink) in the English alphabet ‘H’ are perpendicular lines.

Intersecting lines example

Through the given diagram, we can visualize the difference between perpendicular and non-perpendicular lines.

difference in perpendicular lines


  Fun Facts:

  • Have you ever wondered why 90° is called a right angle? When two lines intersect each other, they form two angles, and when the angles formed are equal, then it is a fair or “right” situation. This is the reason we call 90° as a right angle.

  • An easy way to remember parallel lines is to think of “equal to (=)” sign.


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