28.45 setxunit
-4 5 setxrange
-6 14 setyrange
1 1 settkstep
1 1 setmkstep
ticks
marks
traceaxes
axesarrow
unites

/A {3 5} def
/B {3 -5} def
/C {0 4} def
/D {A C sympoint} def
/E {B C sympoint} def
(A) A [2.5 dup ] urtext
(B) B [2.5 dup ] drtext
(C) C [2.5 dup ] bltext 
(D) D [2.5 dup ] cltext
(E) E [2.5 dup ] ultext
[A B C D E ] {plus3} papply
3 0 times3
3 0 5 pointilles cercle
[A B D E A] continu ligne
[B E] ligne
[A D] ligne

C B 2 marked
E C 2 marked
D C 1 marked
C A 1 marked
A C B angledroit