Viviani's Theorem and its Extensions Revisited; Canghareeb, Sanghareeb   and a New Definition of the Ellipse
  Canghareeb and Sanghareeb are described to be "geometric creatures" living in the plane under certain conditions relative to a triangle. They have common and different features. The former lives on a line segment inside a triangle and the latter lives along an ellipse. Their story ends with a new definition of the ellipse. 
Elias Abboud
math.MG