Try str.Split(new char[] {' '}, StringSplitOptions.RemoveEmptyEntries);.

If my math is correct,x(n) = x + r*cos(a + n*pass)
y(n) = y + r*sin(a + n*pass)
where 0 <= n < vertex, x and y is the center point, a is the angle of the first point to the right of the center...