%% auteur :
-4 8 setxrange
-4 6 setyrange

/I {0 0} def
/A {0 3} def
/B {-2 0} def
/C {2 0} def
/E {-1.2 0}def
/u {4 2} def      
/v {0 -3} def
/w {0 -3.5} def
/x {-3 0} def
/y {0 -0.8} def


/A' {A u addv} def
/C' {C u addv} def
/H' {H u addv} def
/G' {G u addv} def
/F' {F u addv} def

/D'' {C' v addv} def
/B'' {B v addv} def
/C'' {C v addv} def

/B1 {B w addv} def
/C1 {C w addv} def
/A1 {A x addv} def
/I1 {I x addv} def
/E1 {E y addv} def
/I2 {I y addv} def
B1 C1 (<->) line
A1 I1 (<->) line
E1 I2 (<->) line


/d {A I E paral} def
/H {d A B interdroite} def

/d' {B C H paral} def
/G {d' A C interdroite} def

/d'' {A I G paral} def
/F {d'' B C interdroite} def


/fillstyle {.9 setgray fill} def

gsave
   .8 setlinewidth
   [E F G H] polygone*
   
grestore

noir
[A B C] polygone
[E F G H] polygone
[A I] ligne
A I B angledroit
pointilles
   [A A' C' D'' C'' B'' B]ligne
   [C'' C C'] ligne
   [H H' G' F' F] ligne
   [G G'] ligne


setTimesItalic
   (A) A utext
   (B) B dltext
   (C) C drtext
   (I) I dtext
   (E) E dtext
   (F) F dtext
   (G) G utext
   (H) H utext
   (4 m) B1 C1  milieu dtext
   (3 m) A1 I1  milieu rtext
   (x) E1 I2  milieu dtext