不是我证的:
W. Derrick, J. Herstein, Proof Without Words: Ptolemy's Theorem, The College Mathematics Journal, v 43, n 5, November 2012, p 386
不是我证的:
W. Derrick, J. Herstein, Proof Without Words: Ptolemy's Theorem, The College Mathematics Journal, v 43, n 5, November 2012, p 386
• 前面的题,黄兴连开三枪 -got66- ♂ (185 bytes) () 12/26/2017 postreply 20:47:58