50 setxunit
tracerepere
marks
-1 3.5 setxrange
-1.2 3 setyrange
/A {2 0} def
/B {1 -1} def
/C {1 1} def
/I {1 0} def
/I1 {2 1} def
/M {0.5 0.86} def
[A B C] polygone
[A B C M] points
C M droite 
(A) A urtext
(C) C urtext
(B) B drtext
(M) M drtext
(M') 3 1.5 drtext
 I 1 cercle
 I1 1 cercle
(Gamma) 2 -1 urtext
 (Gamma') 2.25 2.25 drtext