คณิตศาสตร์มหัศจรรย์

ที่มา : http://v3math.wordpress.com/2009/06/26/%E0%B8%84%E0%B8%93%E0%B8%B4%E0%B8%95%E0%B8%A8%E0%B8%B2%E0%B8%AA%E0%B8%95%E0%B8%A3%E0%B9%8C%E0%B8%A1%E0%B8%AB%E0%B8%B1%E0%B8%A8%E0%B8%88%E0%B8%A3%E0%B8%A3%E0%B8%A2%E0%B9%8C/