解题方法
1 . 截角四面体是由四面体经过适当的截角,即截去四面体的四个顶点处的小棱锥所得的多面体.如图,将棱长为6的正四面体沿棱的三等分点作平行于底面的截面,得到所有棱长均为2的截角四面体,则( )
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/4/a6255eae-a16e-4156-ab57-61ab91067eb0.png?resizew=406)
A.直线![]() ![]() ![]() |
B.![]() |
C.该截角四面体的表面积为![]() |
D.该截角四面体外接球的表面积为![]() |
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2 . 如图,在四棱锥
中,
平面
,
,
,
,
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/7203f6aa-48c3-45a7-9a64-75981edc4e4f.png?resizew=171)
(1)证明:平面
平面
;
(2)已知二面角
的平面角的余弦为
,求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf7679c8b4b1e442ce4286d4b0e9c32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d47dff1b9d37e2b2cb2afe4bd0c4c04f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/7203f6aa-48c3-45a7-9a64-75981edc4e4f.png?resizew=171)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
(2)已知二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1636b4530c0b42d0e0b649e90e3b9e85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
您最近一年使用:0次
2021-07-21更新
|
1114次组卷
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3卷引用:江西省南昌市豫章中学2021-2022学年高二上学期入学调研(A)数学(理)试题
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3 . 如图,正方体
中,点
为
的中点,点
为
的中点,则下列结论正确的是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/10/ce18a9a6-dd31-4d88-a13a-1d56218551f9.png?resizew=158)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/10/ce18a9a6-dd31-4d88-a13a-1d56218551f9.png?resizew=158)
A.![]() | B.![]() ![]() |
C.![]() ![]() | D.直线![]() ![]() |
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2022-07-08更新
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4卷引用:江西省宜春市第十中学2022-2023学年高二上学期开学考试数学试题
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解题方法
4 . 已知圆锥的顶点为S,母线SA,SB所成的角的余弦值为
,SA与圆锥底面所成的角为45°,若
的面积为
,则圆锥的侧面积为_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72e49817548cb45b3d1e58570644c6fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5528e7af7a80d69178e7db04e64fe0e3.png)
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2021-01-27更新
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3卷引用:江西省赣州市信丰中学2020-2021学年高二下学期入学考试数学(文)试题