program Buffon2
  { Buffon's Needle; www.merlyn.demon.co.uk >= 2001-08-29 } ;
{ NOTE : This is a better demonstration;
  Pi is not used either explicitly or implicitly }
var U, V, W : longint ; X, Y, Z : extended ;
BEGIN ;
W := 1000000 ; Write('Buffon2 ', W, ' ... ') ; V := 0 ; Randomize ;
for U := 1 to W do begin
  { Generate a random point in the unit circle : }
  repeat X := Random ; Y := Random ; Z := Sqr(X)+Sqr(Y) until Z<1 ;
  { Scale to init length, and see if high enough : }
  if Y/Sqrt(Z)>Random then Inc(V) ;
  end ;
Write('"Pi" : ', 2.0/(V/W):0:6, '  <cr>') ; Readln ;
END.