Parallel & Perpendicular Lines

Parallel or Perpendicular?

Example 2

Determine whether the lines are parallel, perpendicular or neither. One line passes through points (-2, -7) and (1, 5); another line passes through points (4, 1) and (-8, 4).

Step 1. Determine the slope of each line.

p_ex2-1

Step 2. Compare the slopes.

The slopes are opposite reciprocals of each other,
so the lines are perpendicular.