園內接四邊形性質：
角ADC=180度-角ABC
角FME
=角FAE+角MEA+角MFA
=角FAE+(180度-角FAE-角ABC)/2+(180度-角FAE-角ADC)/2
=角FAE+(180度-角FAE-角ABC)/2+(180度-角FAE-180度+角ABC)/2
=角FAE+(180度-2*角FAE)/2
=90度
所以EM⊥FM
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由 ☆ ~ 幻 星 ~ ☆ 於 星期一 七月 31, 2006 8:09 pm
[問題]幾何題38
由 tangpakchiu 於 星期一 七月 31, 2006 2:05 pm
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