阳光像花一样
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BD=CD,S△BDE = S△CDE = S△ACE
S△ABC = 3 x S△DCE
根据 △ACE与△DCE的面积相等
可知,A,D到EC的垂线相等 (同底等高)
于是 AF= DF
S△DEF = S△AEF = 1/2
过 F,A 分别向BC做垂线
FG = 1/2 AH
DC = 1/2 BC
S△DFC = 1/4 S△ABC
又 S△DCE =S△DFC + S△DEF
即 1/3 S△ABC = 1/4 S△ABC + 1/2
(1/3 -1/4)S△ABC = 1/2
1/12 S△ABC = 1/2
S△ABC = 6
1年前
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