"The Old Segment a Non-Even Line Trick!"

By:  Pete Rondeau

If you have a line that you need to divide into any number of equal segments, there is a simple drafting technique that does not require dealing with fractions of inches or centimeters.

For Example:
A ten inch line is difficult to divide into three equal segments by measuring.

To perform this "trick" draw the line which you wish to divide (AB in this example)

Draw a line (AZ) perpendicular to line AB from point A.  It's length is unimportant.

Pick a measurement which is larger that line AB and can easily be divided into the desired number of segments.  For this example 12 inches would work well:  It is larger than 10 inches and it can easily be divided into 3 segments (4 inches each).

Draw a new line (BC) to this measurement (12 inches) from point B at an angle which causes its end point C to stop on line AZ.

Divide line BC into the desired numbered of segments.  In this example the line would be marked every 4 inches (X & Y).

Draw lines perpendicular to line AB so they cross line BC at points X and Y.  Erase all of the extra construction lines and you are done!

I learned this in High School and thought it was pretty slick.  I recently used it when drawing a pattern for a parachute gore which required me to divide a 35.5 cm line into 15 sections.