Draw a parallel

In the previous lesson, you used a ruler and a set square to draw perpendicular lines. Today, we will draw a line through a point, parallel 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 parallel to G H. The new line must pass through P. Put the set square along GH. Put a ruler along the set square. The ruler keeps the set square from turning. So its edge keeps the same direction as G H. Slide the set square along the ruler to P. Draw the line through P. The new line goes the same way as G H. The gap between them stays the same, so they never meet. They are parallel. Lift the set square aside, then move the ruler beside it. Draw matching arrows. 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 parallel to J K. Try it first. Pause if you like. The new line must pass through Q. Put the set square along JK. Put a ruler along the set square. Slide the set square along the ruler to Q. Draw the line through Q. Lift the set square aside, then move the ruler beside it. Draw matching arrows.

Harpreet draws a line L M and marks a point R. Use a ruler and a set square to draw a line through R that is parallel to L M. Try it first. Pause if you like. The new line must pass through R. Put the set square along LM. Put a ruler along the set square. Slide the set square along the ruler to R. Draw the line through R. Lift the set square aside, then move the ruler beside it. Draw matching arrows. The new line must go through the point. It keeps the same direction, so the two lines never meet.