Draw a perpendicular

In the previous lesson, you learned that perpendicular lines meet at a right angle. Today, we will draw a line through a point, perpendicular to another line. Harpreet draws a line G H and marks a point P. Use a ruler and a set square to draw a line through P that is perpendicular to G H. The new line must pass through P. Place a ruler along G H. Put the set square against the ruler. The corner of a set square is a right angle. So its two edges are perpendicular. Slide it until its edge touches P. We draw along the edge that goes through P. This new line meets G H at a right angle. Lift the set square aside, then move the ruler aside. Mark the right angle. We have answered the question.

Harpreet draws a line J K and marks a point Q. Use a ruler and a set square to draw a line through Q that is perpendicular to J K. Try it first. Pause if you like. The new line must pass through Q. Place a ruler along J K. Put the set square against the ruler. Slide it until its edge touches Q. Draw the line through Q. Lift the set square aside, then move the ruler aside. Mark the right angle.

Harpreet draws a line R S and marks a point T above it. Use a ruler and a set square to draw a line through T that is perpendicular to R S. Try it first. Pause if you like. The new line must pass through T. Place a ruler along R S. Put the set square against the ruler. Slide it until its edge touches T. Draw the line through T. Lift the set square aside, then move the ruler aside. Mark the right angle. The new line must go through the point. It must meet the first line at a right angle.