From Gogeometry Using Additional points Inscribed angles in a circle congruent triangles Concyclic points Solution of a previous problem : 496 CK⊥ KH and CE⊥ EH =>CKEHJ are concyclic=> ∠EKC= 3Π/2= ∠EKJ + ∠JKC = ∠EKJ + ∠JEC = ∠EKJ + Π/2=> ∠EKJ= Π/2K and I on GJ, IE⊥ GJ […]