To make a threlike triangle on any lyne measurable.
Take the iuste length of the lyne with your compasse, and stay the
one foot of the compas in one of the endes of that line, turning
the other vp or doun at your will, drawyng the arche of a circle
against the midle of the line, and doo like wise with the same
compasse vnaltered, at the other end of the line, and wher these
ij. croked lynes doth crosse, frome thence drawe a lyne to ech
end of your first line, and there shall appear a threlike
triangle drawen on that line.
[Illustration]
_Example._
A.B. is the first line, on which I wold make the threlike
triangle, therfore I open the compasse as wyde as that line is
long, and draw two arch lines that mete in C, then from C,
I draw ij other lines one to A, another to B, and than I haue my
purpose.