Hi Kevin
I really do not see the advantage in cutting the segments that way Could you
please explain why it is done in that manner.

Looking at the picture it seems to me that as you true the circle up you end
up with a trapeziod any way.

Sorry I cant help with the math but I can give you the formulas for the
normal trapezoid segments. Either just as a mathematical formula or as a
formula for a spreadsheet.

Tom