[Woodcarver] geometry - labyrinth layout

[Sean Carney]

'Lo Vic
Sorry I didn't read your question sooner.  I'm a math major, and I can help
a bit.  What you're looking for is a chord length to help you lay this thing
out, and a chord is any line segment connecting two points on a circle.
Y'all have already figured out what your central angle is, which is 360/13.
The formula of a chord is 2r sin(theta/2), where r is your radius and theta
is the central angle in radians (instead of 360/13, think 2pi /13).  For an
18" square board, your max radius is 9", so according to my calculator 2 *
9" * sin (2pi/26) = 4.3076", which is a little less than 4 5/16".  Just set
your compass to 4 5/16", draw a line from the center of the circle to the
edge of it, put the sharp point of the compass where the line and circle
meet, and draw an arc that intersects the circle.  Draw a line from the
center of the circle to where the arc intersected the circle.  You have just
created a 1/13th division of the circle, so repeat as neccessary with your
compass and fairly soon you'll have it all laid out.
Thanks, by the way, for asking this question.  My future students will have
one killer extra credit problem now ;-)

Sean