由 Searchtruth 於 星期六 三月 15, 2003 10:29 pm
在AE上作一點P~且AE垂直PF
=>AP=PF
現在設DF=t ,
=>CE=t+1 , AB=AD=t+3
=>AP=﹛(AD^2+DF^2)/2﹜1/2
=>PE=(AB^2+BE^2)1/2 - AP
=>EF^2=PE^2+PF^2=EC^2+FC^2
=>[((AB^2+BE^2)1/2 - ﹛(AD^2+DF^2)/2﹜1/2)]2+(AD^2+DF^2)/2=(t+1)^2+3^2
=>t=3 , 還有兩ㄍ虛根...不合
=>邊長=t+3=6
=>EF^2=3^2+4^2
=>EF=5
我絕ㄉ這ㄍ算法太冗長ㄌ...>"<