%@AUTEUR:Guillaume Connan

prologues:=2;

verbatimtex
%&latex
\documentclass{article}
\usepackage[upright]{fourier}
\begin{document}
etex

input geometriesyr16

figure(-10cm,-5cm,12cm,10cm);
pair a,b,c,d,o,m,n,p,q;
path pp,r;
a=origin;
b=(4u,0);
d=(u,3u);
c=b+d;
o=.5c;
q=1.5[d,a];
p=1.5[c,d];
n=1.5[b,c];
m=1.5[a,b];
pp=a--b--c--d--cycle;
r=m--n--p--q--cycle;
fill r withcolor .9white;
fill pp withcolor .8white;

trace pp withpen pencircle scaled 1.8bp withcolor .4white;
trace r withpen pencircle scaled 1.8bp withcolor .6white;
trace codesegments(a,o,o,c,2);
trace codesegments(b,o,o,d,4);
trace Codelongueur(a,.5[a,b],.5[a,b],b,b,m,1);
trace Codelongueur(b,.5[b,c],.5[b,c],c,c,n,5);
trace Codelongueur(c,.5[c,d],.5[c,d],d,d,p,1);
trace Codelongueur(d,.5[d,a],.5[d,a],a,a,q,5);
 
trace a--c;
trace b--d;
trace b--m;
trace c--n;
trace d--p;
trace a--q;

label.bot(btex A etex,a);
label.bot(btex B etex,b);
label.top(btex C etex,c);
label.top(btex D etex,d);
label.lft(btex O etex,o);
label.bot(btex Q etex,q);
label.bot(btex M etex,m);
label.top(btex N etex,n);
label.top(btex P etex,p);
dotlabel.bot(btex  etex,.5[a,b]);
dotlabel.bot(btex  etex,.5[b,c]);
dotlabel.bot(btex  etex,.5[c,d]);
dotlabel.bot(btex  etex,.5[d,a]);
fin;

end