(几何证明选讲选做题)已知AD是△ABC的外角∠EAC的平分线,交BC的延长线于点D,延长DA交△ABC的外接圆于点F,连接FB,FC.
(1)求证:FB=FC;
(2)若AB是△ABC外接圆的直径,∠EAC=120°,BC=3
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231537909158566/SYS201311012315379091585020_ST/0.png)
,求AD的长.
考点分析:
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