# Constructing a perpendicular to a line through a point

This is the step-by-step, printable version. If you PRINT this page, any ads will not be printed.

After doing this Your work should look like this
Start with a line and point R which is not on that line. Step 1 Place the compasses on the given external point R. Step 2 Set the compasses' width to a approximately 50% more than the distance to the line. The exact width does not matter. Step 3 Draw an arc across the line on each side of R, making sure not to adjust the compasses' width in between. Label these points P and Q Step 4 At this point, you can adjust the compasses' width. Recommended: leave it as is.

From each point P,Q, draw an arc below the line so that the arcs cross. Step 5 Place a straightedge between R and the point where the arcs intersect. Draw the perpendicular line from R to the line, or beyond if you wish. Step 6 Done. This line is perpendicular to the first line and passes through the point R. It also bisects the segment PQ (divides it into two equal parts) 