%% auteur : Gilles Mora

-5 3 setxrange
-3 4 setyrange
40 setxunit
40 setyunit
/N{-4 3} def
/Z{0 0 } def

/M{Z N 36 rotatepoint} def
/P{N M 108 rotatepoint} def
[N P M] polygone
[ M Z] ligne
[M N N Z M P ]{2 marked} dapply

/arrowscale {1.5 dup} def
/arrowangle -5 def
Z N M  0.6 (-) tripointarcarrow


setTimes
(N) N [2 2] ultext
(Z) Z [2 2] dltext
(M) M [2 2] utext
(P) P [2 2 ] dtext
(36°) -3.3 2.5 [1.5 1.5] text