End T11_1.
Section T11_2.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma angle_construction_4 :
forall A B C A' B' P,
A <> B -> C <> B -> A' <> B' ->
exists C', CongA A B C A' B' C' /\ Coplanar A' B' C' P.