Lemma EmbeddedSimilarTriangles : forall A B C : Point, forall n : nat, Clockwise A B C -> n > 0 -> forall D E : Point, HalfLine A B D -> HalfLine A C E -> Distance A D = DistTimesn n A B -> Distance A E = DistTimesn n A C -> Angle A B C = Angle A D E /\ Angle A C B = Angle A E D.