Name the Triangle

              What is the name of the triangle formed by joining the facet of the perpendiculars from the vertices of a triangle to the opposite side? 

Answer: Pedal: this triangle is also called the Orthocentric triangle.

              If A.D, BE and CF are the perpendiculars dropped from the vertices of the triangle ABC to the opposite sides, then the triangle DEF is the pedal triangle.

The three perpendiculars pass through a common point called the Orthocentre.