Draw any line segment ¯¯¯¯¯¯¯¯AB. Mark any point M on it. Through M, draw a perpendicular to ¯¯¯¯¯¯¯¯AB. (Use ruler and compasses)
Draw any line segment PQ¯. Mark any point M on it . Through M, draw perpendicular to PQ¯ (use ruler and compasses).
Draw any line segment AB. Mark any point M on it. Through M, draw a perpendicular to AB(use ruler and compasses).