✔ 最佳答案
圖片參考:
https://s.yimg.com/rk/AD06198854/o/666990443.png
A=(0,0), F=(3,0), B=(5,0), C=(3,3√3)=> BC=√[(5-3)^2+(3√3)^2]=√31=5.57
2014-05-21 04:59:24 補充:
ΔBCD: b>c => CD>BC=√31
ΔABC: AC=6, AB=5, BC=√31
ΔABD: AC=6, AD=5, CD>√31
BC對應CAB=60(deg) => CD>√31對應DAC>60(deg)
2014-05-21 09:20:10 補充:
修正:
ΔABC: AC=6, AB=5, BC=√31 => 對應CAB=60(deg)
ΔACD: AC=6, AD=5, CD>√31 => 對應DAC>60(deg)