-10 8 setxrange -5 7 setyrange /I {2 -1} def /alpha 50 def /v {6 5} def /A {0 0} def /B {0 4.5} def /C {-9 3 sqrt mul 2 div 0} def /A1 {A I alpha rotatepoint} def /B1 {B I alpha rotatepoint} def /C1 {C I alpha rotatepoint} def /P {A1 v addv} def /M {B1 v addv} def /N {C1 v addv} def [A B C] polygone C A B angledroit [P M N] polygone N P M angledroit %% [A1 B1 C1] points %% [P M N] (times2) plot A C B 1.5 (-) tripointarc N M P 1 (-) tripointarc setTimesItalic (A) A drtext (B) B urtext (C) C dltext (P) P rtext (M) M utext (N) N dtext setTimes (30°) C 1.65 .35 addv text (60°) M 0 -1.5 addv text (4,5) M P milieu utext $$ {9\sqrt 3\over 2} $$ A C milieu dctexlabel