%% auteur : 

-1 3 setxrange
-1 2 setyrange
100 setxunit
%% definition des points
/A {1 1.732} def
/B {0 0} def
/C {2 0} def
/H {1 0} def
/E {-0.732 0} def
[A B C] polygone
[A H] ligne

A H C angledroit
continu
B A H .2 tripointarc
H A C 0.3  tripointarc
C B A 0.2 tripointarc
A C B 0.2 tripointarc
A B 2 marked
A C 2 marked
B H 3 marked
C H 3 marked
setTimesItalic
   (A) A [2 2] ultext
   (B) B [2 2] ultext
   (C) C [2 2] rtext
   (H) H [2 2] dltext
(4) A C milieu [1.3 1.3] urtext
<tex>
$$
   {2\sqrt 3}
$$
</tex>

A H milieu [1.3 dup] dltexlabel
 setTimes
   (60°) 20 B 0.3 cpoint cctext
(60°) 140 C 0.3 cpoint cctext
   (30°) -100 A 0.3 cpoint cctext
 (30°) -70 A 0.4 cpoint cctext