Constructing Perpendicular Lines

How to construct perpendicular lines using a compass and a straight edge.

Step 1:

Draw a line with your straight edge and put two points on them. Label one A and the other one B.

Step 2:

Draw an arch with your compass on B to the right.

Step 3:

Draw an arch with your compass on B to the left.

Step 4:

Draw an arch with your compass on A to the left. It should intersect with the arch you drew to the left on B.

Step 5:

Draw an arch with your compass on A to the right. It should intersect with the arch you drew to the right on B.

Step 6:

Connect the two intersection of the archs to create perpendicular lines.