A Relation between Altitudes of Four Triangles

Let ABC be a triangle and DEF be parallel to AC and FGM be parallel to AB. Let AH, DN, FP, and MQ be altitudes in triangles ABC, DBE, FEG, and MGC respectively. Then with the plus sign when F is outside of ABC and minus when F is inside.



  • [Snapshot]
  • [Snapshot]
  • [Snapshot]


The statement of the theorem is in Problem 91. Similar Triangles, Altitudes, Parallel.
    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.