BACK TO SCHOOL
"The Old Segment a Non-Even Line
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.
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