-2 10 setxrange
-2 6 setyrange

%traceaxes
%marks

/A {0 0} def
/B {0 4} def
/M {8 0} def

%%%%%%%%%%%%%%%%%%%%%%%%%%%

/O {A B milieu} def
/E {A M milieu} def
/F {B M milieu} def

1 dict begin
   medium setlinewidth
   [A B M] polygone
end

[O F E] points
A B diamcercle cercle
B A M angledroit

%%%%%%%%%%%%%%%%%%%%%%%%%%%

O F droite
F B IAcercle cercle
A O F angledroit

pointilles
B E droite
O M droite
A F droite
O M A F interdroite /K defpoint

K point

setTimesItalic
   (A) A dltext
   (B) B ultext
   (M) M drtext
   (F) F urtext
   (E) E drtext
   (O) O urtext
   (K) K utext