Require Export B6_Cercle_Def.
Section EQUILATERAL_TRIANGLE.
Definition Equilateral (A B C : Point) :=
Distance A B = Distance A C /\
Distance A B = Distance B C.

Lemma Exists2AB : forall A B : Point,
A <> B ->
{C : Point |
Between A B C /\
Distance B C = Distance A B}.