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已知:Rt△ABC中,∠ACB=90°,CD平分∠ACB交AB于点D,点F为边A...
已知:Rt△ABC中,∠ACB=90°,CD平分∠ACB交AB于点D,点F为边AB的中点,EF∥CD交BC于点E,则下列结论:
①AC=
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EF;②BC-AC=2CE;③EF=
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CE;④EF•AB=
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AD•BE;
其中一定成立的是( )
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A.①②④
B.③④
C.①②③
D.①②
考点分析:
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