autocrop -2 5 setxrange -2 5 setyrange /A {0 0} def /C {4.2 0} def A 2.8 C 3.9 intercercle /B defpoint popp /I {A B milieu} def %% l'angle ACB 180 C B angle sub /alpha exch def %% la droite (ID) I dupp alpha dir A C interdroite /D defpoint [I D] ligne A I D .5 (-) tripointarc B C A .5 (-) tripointarc A I 1 marked I B 1 marked 1.5 setlinewidth [A B C] polygone setTimesItalic (A) A dltext (B) B urtext (C) C drtext (D) D drtext (I) I ultext