Perpendicular Lines

In geometry, two lines are said to be perpendicular if they intersect at a right angle (90 degrees). This means that the lines form four right angles where they meet. The symbol for perpendicular lines is ⊥.

How to Identify Perpendicular Lines

To identify perpendicular lines, you can use a protractor to measure the angle formed by the two lines where they intersect. If the angle measures 90 degrees, then the lines are perpendicular.

Examples of Perpendicular Lines

Some common examples of perpendicular lines are the sides of a square or rectangle, the legs of a right triangle, and the axes of a coordinate plane.

Properties of Perpendicular Lines

Perpendicular lines have a few important properties:

• They intersect at a right angle (90 degrees).
• The slopes of perpendicular lines are negative reciprocals of each other. If the slope of one line is m, then the slope of the perpendicular line is -1/m.
• They form right angles where they intersect.