Two Triangles with the Same Orthocenter and a Vectorial Proof of   Stevanovic's Theorem
  In this article we'll emphasize on two triangles and provide a vectorial proof of the fact that these triangles have the same orthocenter. This proof will further allow us to develop a vectorial proof of the Stevanovic's theorem relative to the orthocenter of the Fuhrmann's triangle. 
Ion Patrascu, Florentin Smarandache
math.GM