A Short Tour of Triangle Geometry
Around the Nine-point Circle
Paul Yiu
Department of Mathematics
Florida Atlantic University
April 14, 2007

  1. Nine-point circle and Euler line
  2. Incircle and excircles
  3. Some interesting triads of circles
  4. Fermat points and Napoleon theorem
  5. Inscribed equilateral triangles
  6. Reflections and isogonal conjugates
  7. Simson line theorem and line of reflections
  8. Triangle of reflections