YLL討論網

#ed_op#DIV#ed_cl#原來題目是錯的....害我算了那麼久.....#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#thx asmobia and 幻星~~~#ed_op#/DIV#ed_cl#

tangpakchiu 寫到:#ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#IMG alt="image file name: 2kd1f6746523.gif" src="http://yll.loxa.edu.tw/phpBB2/richedit/upload/2kd1f6746523.gif" border=0#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#ΔABC為一全等三角形,P在BC劣弧內,求證OEPF為一平行四邊形.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl#

#ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#一.  依圖中所知, 角AFP 為直角, 故 #ed_op#U#ed_cl#FP#ed_op#/U#ed_cl# 垂直於 #ed_op#U#ed_cl#AF#ed_op#/U#ed_cl# .#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#二.  假設 #ed_op#U#ed_cl#OE#ed_op#/U#ed_cl# 平行於 #ed_op#U#ed_cl#FP#ed_op#/U#ed_cl#, 則依據第一點, 得知 #ed_op#U#ed_cl#OE#ed_op#/U#ed_cl# 垂直於 #ed_op#U#ed_cl#AF#ed_op#/U#ed_cl# ( #ed_op#U#ed_cl#AB#ed_op#/U#ed_cl# ).#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#       也就是說 #ed_op#U#ed_cl#OE#ed_op#/U#ed_cl#  是過圓心且與內接正三角形之一邊垂直的線,#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#       所以說 E 點也應該就是 C 點.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#三,  依據第二點結論, #ed_op#U#ed_cl#FE#ed_op#/U#ed_cl# = #ed_op#U#ed_cl#FC#ed_op#/U#ed_cl#.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#四,  #ed_op#U#ed_cl#FE#ed_op#/U#ed_cl#  與 #ed_op#U#ed_cl#BC#ed_op#/U#ed_cl# 相交於 D, 依據第三點, 得知 #ed_op#U#ed_cl#FC#ed_op#/U#ed_cl#  與 #ed_op#U#ed_cl#BC#ed_op#/U#ed_cl# 相交於 D 點.       #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#       故 D 點也應該就是 C 點 .#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#五,  依據第四點結論, P 點也應該就是 C 點.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#所以說, " #ed_op#U#ed_cl#OE#ed_op#/U#ed_cl# 平行於 #ed_op#U#ed_cl#FP#ed_op#/U#ed_cl# "之假設非真, OEPF 不為一平行四邊形.#ed_op#/DIV#ed_cl#

確定題目沒錯嗎??

我畫出來不是欸..

#ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#IMG alt="image file name: 2kd1f6746523.gif" src="http://yll.loxa.edu.tw/phpBB2/richedit/upload/2kd1f6746523.gif" border=0#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#ΔABC為一全等三角形,P在BC劣弧內,求證OEPF為一平行四邊形.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl#