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如图,在同心圆中,两圆半径分别为2,1,∠AOB=120°,则阴影部分的面积为(...
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如图,在同心圆中,两圆半径分别为2,1,∠AOB=120°,则阴影部分的面积为( )
A.4π
B.2π
C.
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D.π
考点分析:
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长为( )
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A.
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B.
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C.
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A.三条高的交点
B.三个内角平分线的交点
C.三条角平分线的交点
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A.
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D.
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