About pi. I find it funny that people say that one can calculate the periphery of a circle but not of an ellipse when the periphery of circle is 2*pi*r and ellipse is 4*a*E(e), where r is the radius of the circle, a is the larger semiaxis of the ellipse and e is the excentricity of the ellipse. pi and E(e) are both as difficult to calculate exactly but somehow people say that the other equation is explicit and the other is not.####[]