The fractional values of n between whole numbers are totally meaningless.
Is the 36 degree figure mentioned, is it a ten sided figure? Why do you measure that angle, and not the
one you can actually see? 180 - 36 degrees. Probably because 36 times 10 is 360.
V = 360 / n, for n integers > 1. (or 2 if you want to start with a triangle)
Or maybe the hint is that the 36 degree angle is the angle in the point of a
five pointed star? If that is the case, then
V = 180 - (360 / n)