→ musicbox810 :可是E點不在AC上阿 06/10 21:50
→ justin0602 :圖上的E和F要顛倒才對 06/10 21:57
→ justin0602 :或應該說BC要顛倒 06/10 21:58
推 ipost :ABC內找一點P使得角FDC等於角FCP且DC等於DP,P會在EF 06/11 02:24
→ ipost :上故CF=PF BE=PE 得證 06/11 02:25
→ ipost :更正是角FDC=角FDP 06/11 11:29