... http://en.wikipedia.org/wiki/Ptolemy's_theorem Internet, Simson’s Line and Its Applications http://www.math.uci.edu/~mathcirc/math194/lectures/inscribed/node2.html Internet, Casey’s Theorem – Generalized Ptolemy’s ... Sawayama and Thebault’s Theorem, Forum Geometricorum, Volume (2003), 225-229 http://forumgeom.fau.edu/FG2003volume3/FG200325.pdf 11 Internet, Ptolemy’s Table of Chords Trigonometry in the second...