Because there exists only one line perpendicular to a line at a given point, a segment has only one perpendicular bisector: the perpendicular line that passes through the midpoint of the segment. Figure %: A perpendicular bisector The line CD contains the midpoint of segment AB, and forms a right angle with the segment. Therefore, it is the perpendicular bisector of segment AB. Just as there are bisectors for segments, there are trisectors, too. Segment trisectors divide a segment into three ...