hgb>Even more bizarre, IMHO, is the fact that in the volume formula for n dimensions, it isn't pi itself, but sqrt(pi), that is important. That's sort of a notational artifact: (c41) sphere_volume(n,r) n/2 n %pi r (d41) --------- n (-)! 2 How times have changed. Last night I showed a 6th grader how to numerically solve for the length of the chord that cuts off area pi/3 from the unit circle (1.92853414856779, not in ISC), and the first thing he asked was "Can you prove it's irrational?". I'll bet the smart Greeks had the concept of real number, but had no way to market it. --rwg PS, if you start with 2 in the Newton's method for the disk trisection problem, you're stuck on 2 ! Look Ma, no Yahoo spamdangles!