%% auteur : Florent Braisaz

-4.9 4.9 setxrange
-4.9 4.9 setyrange
15 setxunit
15 setyunit

/A {-3.5 -3.5} def
/B {-1 2} def
/C {3.5 -3.5} def
/H {B A C orthoproj} def

1.25 setlinewidth

[A B C] polygone

gsave
rouge
B H droite
#latex# ${\Delta}$ 
-1 3.5 [1.5 dup] urtexlabel
C H B angledroit
grestore


gsave
setTimesItalic
(A) A [1.5 1.5] cltext
(B) B [1.5 1.5] urtext
(C) C [1.5 1.5] crtext
(H) H [1.5 1.5] dltext
grestore