
 Articles  Pi (Site not responding. Last check: 20071018) 
  In Euclidean plane geometry, Ï may be defined either as the ratio of a circle's circumference to its diameter, or as the ratio of a circle's area to the area of a square whose side is the radius. 
  Because the coordinates of all points that can be constructed with ruler and compass are constructible numbers, it is impossible to square the circle, that is, it is impossible to construct, using ruler and compass alone, a square whose area is equal to the area of a given circle. 
  Nehemiah, a late antique Jewish rabbi and mathematician explained this apparent lack of precision in Ï, by considering the thickness of the basin, and assuming that the thirty cubits was the inner circumference, while the ten cubits was the diameter of the outside of the basin. 
 www.worldmapa.com /articles/Pi (2720 words) 
