如图,已知等边△ABC中,AB=8.以AB为直径的半⊙O与边AC相交于点D.过点D作DE⊥BC,垂足为E,过点E作EF⊥AB,垂足为F、连接DF.
![](https://img.xkw.com/dksih/QBM/2019/12/8/2350796364587008/2351485597687808/STEM/552ed9be674741ada8379db69ba39fbd.png?resizew=164)
(1)求证:DE是⊙O的切线
(2)求EF的长;
(3)求sin∠EFD的值.
![](https://img.xkw.com/dksih/QBM/2019/12/8/2350796364587008/2351485597687808/STEM/552ed9be674741ada8379db69ba39fbd.png?resizew=164)
(1)求证:DE是⊙O的切线
(2)求EF的长;
(3)求sin∠EFD的值.
更新时间:2019-12-09 16:52:36
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【推荐1】如图,AB为⊙O的直径,点C为半圆上一点,AD平分∠CAB交⊙O于点D
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![](https://img.xkw.com/dksih/QBM/2018/2/19/1885690803273728/1895492468310016/STEM/8f483aef6c7547a28d4462457167c724.png?resizew=151)
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