Ptolemy's Theorem

Let ABCD be a quadrilateral where all the vertices lie on a circle. As long as the (green) diagonals cross, ; in words, the sum of the products of the two pairs of opposite sides equals the product of the diagonals.
Drag any vertex to another location on the circle.



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