Perpendicular

Definition

Perpendicular lines are two lines that intersect at a right angle (90 degrees). In the context of linear equations, their slopes are negative reciprocals of each other.

5 Must Know Facts For Your Next Test

1. The product of the slopes of two perpendicular lines is -1.
2. If a line has a slope m, a line perpendicular to it will have a slope of -1/m.
3. Perpendicularity is often used to find equations of lines given certain conditions.
4. In coordinate geometry, the concept helps in solving problems involving right triangles and distances.
5. The intersection point of two perpendicular lines forms four 90-degree angles.

Review Questions

• What is the relationship between the slopes of two perpendicular lines?
• If a line has a slope of 3, what is the slope of a line perpendicular to it?
• How can you determine if two given linear equations represent perpendicular lines?

Related terms

Slope: A measure of how steep a line is, calculated as the ratio of rise over run.

Linear Equation: An equation that makes a straight line when it is graphed. Typically written in the form y = mx + b.

Negative Reciprocal: The opposite inverse of a number. For example, the negative reciprocal of 3 is -1/3.