% This figure illustrates Pascal's theorem.
% Copyright (c) Christian Obrecht 2001
box(-3,-4,7,8,1.5)
El = ellipse(point(0,0),2,1,0:)
A = point(El,0)
B = point(El,pi/5)
C = point(El,2*pi/3)
D = point(El,pi)
E = point(El,3*pi/2)
F = point(El,11*pi/6)

AB = line(A,B)
BC = line(B,C)
CD = line(C,D)
DE = line(D,E)
EF = line(E,F)
FA = line(F,A)

I = intersection(AB,DE)
J = intersection(FA,CD)

draw(AB,dotted) ; draw(BC,dotted)
draw(CD,dotted) ; draw(DE,dotted)
draw(EF,dotted) ; draw(FA,dotted)
draw(line(I,J))
color(white)
draw(A,B,C,D,E,F)
color(black)
draw(A,B,C,D,E,F,dashed)
draw(El)