Slopes of Perpendicular Lines 1

Perpendicular Lines

Two lines are perpendicular when they intersect at 90 degree angles. Two lines are graphed in the plane. The slope of the first line is a/b. The slope of the second line is c/d. Change the values of a, b, c, and/or d and make note of the angle between the lines.

Slopes of Perpendicular Lines

Slopes of Perpendicular Lines

By examining the equations, how do you know when two lines will be perpendicular when graphed?