Require Export C11_Mediatrice.
Section OPPOSED_ANGLE.

Lemma CongruentOpposedStrictTriangles : forall A B C D I : Point,
Between A I C ->
Between B I D ->
Distance I A = Distance I C ->
Distance I B = Distance I D ->
~Collinear A I B ->
CongruentStrictTriangles A I B C I D.