
 A Versatile Theorem 
  The applet illustrates a theorem that can be used to establish the Minimax Theorem for twoperson zerosum games. 
  The theorem is just a particular case of Pappus' theorem: if (there) AbaB, then, since Ab·aB, Bc·bC, and Ca·cA are collinear, the line through Bc·bC and Ca·cA is parallel to both Ab and aB. 
  This is exactly the statement of the theorem at hand, where D and E replace B and C, while B, C, F replace a, b, and c. 
 www.cuttheknot.org /Curriculum/Geometry/MMParallel.shtml (235 words) 
