http://meljohra.blogspot.com/p/blog-page_6766.html
http://istidlalmaths.voila.net/pagesweb/ppythagore.htm
imamali.orgfree.com/Math/math.../006.doc
http://mathsalmi.hooxs.com/t68-topic
http://www.blogger.com/blogger.g?blogID=27603234#editor/src=dashboard
https://docs.google.com/file/d/0Bxuq37v5c0keZDBhMWEyZWItZWUyMy00MmE5LWE0MDktOTczZGI4ZGQ1NTQ1/edit?pli=1
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