Dynamic Geometry: Nine Point Circle or Euler's Circle or Feuerbach
Circle of a Triangle.
HTML5 Animation for Tablets
Nine Point Circle or Euler's
Circle or Feuerbach Circle
The nine point circle of a triangle ABC is the circle that passes through
nine significant concyclic points: the feet HA, HB, and HC,
of the altitudes,
the midpoints MA, MB, and MC, of each
side and the midpoints EA, EB, and EC of
the segment from each vertex to the orthocenter.