Draw a line and a point on it. Through , draw a line segment perpendicular to .Now draw a perpendicular to at . (use ruler and compasses)
Step 1: Draw a line l and mark a point X on it.
Step 2: Take as centre and with a convenient radius, draw an arc intersecting the line at points A and B, respectively.
Step 3: Take A and B as centres and a radius more than AX, construct two arcs such that they intersect each other at point Y.
Step 4: Join XY. Here is perpendicular to .
Step 5: Take C and D as centers and radius more than CY, construct two arcs intersecting at point Z. Join ZY. The line ia perpedicular to the line .