Perpendicular Lines and Slopes

perpendicular Two lines are perpendicular if and only if the product of their slopes is -1 If the slopes of two lines which are perpendicular are m1

perpendicular to, perpendicular with Objects at a 90 ° angle are perpendicular to one another Perpendicular with is non-standard In formal writing, do not perpendicular Perpendicular lines: Always meet at right angles; Have four 90° angles that add up to 360°; Can only be made up of one perpendicular line at a given point