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            • 1.

              水平放置的排水管\((\)圆柱体\()\)截面半径是\(1 cm\),水面宽也是\(1 cm\),则截面有水部分\((\)弓形\()\)的面积是 (    )

              A.\(\left( \dfrac{{ }\!\!\pi\!\!{ }}{{6}}-\dfrac{\sqrt{{3}}}{{4}} \right)\ {c}{{{m}}^{{2}}}\)
              B.\(\left( \dfrac{{5 }\!\!\pi\!\!{ }}{{6}}+\dfrac{\sqrt{{3}}}{{4}} \right)\ {c}{{{m}}^{{2}}}\)
              C.\(\left( \dfrac{{ }\!\!\pi\!\!{ }}{{6}}-\dfrac{{3}}{{2}} \right)\ {c}{{{m}}^{{2}}}\)
              D.\(\left( \dfrac{{ }\!\!\pi\!\!{ }}{{6}}-\dfrac{\sqrt{{3}}}{{4}} \right)\ {c}{{{m}}^{{2}}}\)或\(\left( \dfrac{{5 }\!\!\pi\!\!{ }}{{6}}+\dfrac{\sqrt{{3}}}{{4}} \right)\ {c}{{{m}}^{{2}}}\)
            • 2.
              将等腰\(Rt\triangle ABC\)绕点\(A\)逆时针旋转\(15^{\circ}\)得到\(\triangle AB′C′\),若\(AC=1\),则图中阴影部分面积为\((\)  \()\)
              A.\( \sqrt {3}\)
              B.\(3 \sqrt {3}\)
              C.\( \dfrac { \sqrt {3}}{3}\)
              D.\( \dfrac { \sqrt {3}}{6}\)
            • 3.

              一个扇形的圆心角是\(120^{{∘}}\),面积为\(3\pi cm^{2}\),那么这个扇形的半径是\(({  })\)

              A.\(1cm\)                           
              B.\(3cm\)                           
              C.\(6cm\)                           
              D.\(9cm\)
            • 4.

              如图,以\(AB\)为直径,点\(O\)为圆心的半圆经过点\(C\),若\(AC=BC=\sqrt{2}\),则图中阴影部分的面积是\((\)    \()\)

              A.\(\dfrac{\mathrm{ }\!\!\pi\!\!{ }}{4}\)
              B.\(\dfrac{1}{2}+\dfrac{\mathrm{ }\!\!\pi\!\!{ }}{4}\)
              C.\(\dfrac{\mathrm{ }\!\!\pi\!\!{ }}{2}\)
              D.\(\dfrac{1}{2}+\dfrac{\mathrm{ }\!\!\pi\!\!{ }}{2}\)
            • 5.

              如图,在\(Rt\triangle ABC\)中,\(∠ACB=90^{\circ}\),\(AC=BC=1\),将\(Rt\triangle ABC\)绕点\(A\)逆时针旋转\(30^{\circ}\)后得到\(Rt\triangle ADE\),点\(B\)经过的路径为\(\overset\frown{BD}\),则图中阴影部分的面积是(    )




              A.\(\dfrac{{ }\!\!\pi\!\!{ }}{{6}}\)
              B.\(\dfrac{{ }\!\!\pi\!\!{ }}{{3}}\)
              C.\(\dfrac{{ }\!\!\pi\!\!{ }}{{2}}-\dfrac{{1}}{{2}}\)
              D.\(\dfrac{1}{{2}}\)
            • 6.

              半径为\(5\)的圆的面积是(    )

              A.整数
              B.分数
              C.有理数
              D.无理数
            • 7. 半径为\(6\),圆心角为\(120^{\circ}\)的扇形的面积是\((\)  \()\)
              A.\(3π\)       
              B.\(6π\)         
              C.\(9π\)        
              D.\(12π\)
            • 8.

              如图,一扇形纸扇完全打开后,外侧两竹条\(AB\)和\(AC\)的夹角为\(120^{\circ}\),\(AB\)长为\(25cm\)。贴纸部分的宽\(BD\)为\(15cm\),若纸扇两面贴纸,则贴纸的面积为(    )

              A.\(175πcm^{2}\)
              B.\(350πcm^{2}\)
              C.\(\dfrac{800}{3}\mathrm{ }\!\!\pi\!\!{ }cm^{2}\)
              D.\(150πcm^{2}\)
            • 9.

              一圆锥的侧面展开图的圆心角为\(120^{\circ}\),该圆锥的侧面积与全面积之比值为(    )

              A.\( \dfrac{3}{4} \)    
              B.\( \dfrac{2}{3} \)    
              C.\( \dfrac{4}{5} \)    
              D.\( \dfrac{1}{2} \)
            • 10.

              如图,点\(A\)、\(B\)、\(C\)在\(⊙O\)上,若\(∠BAC=45^{\circ}\),\(OB=2\),则图中阴影部分的面积为(    )




              A.\(π-2 \)
              B.\(π-4 \)
              C.\( \dfrac{1}{2}π-2 \)
              D.\( \dfrac{1}{2}π+2 \)
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