名校
1 . 为了求一个棱长为
的正四面体体积,小明同学设计如下解法:构造一个棱长为1的正方体,如图1:则四面体
为棱长是
的正四面体,且有
.学以致用:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/13/7f6e930f-e5a9-4fb1-a52c-5d884c18416e.png?resizew=304)
(1)如图2,一个四面体三组对棱长分别为
,2,
,求此四面体外接球表面积;
(2)若四面体ABCD每组对棱长分别相等,求证:该四面体的四个面都是锐角三角形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68ac02c2f91cadb1e328bc6ab9b9c491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff5e6b8c4de00d7e01238f7a32c19429.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/13/7f6e930f-e5a9-4fb1-a52c-5d884c18416e.png?resizew=304)
(1)如图2,一个四面体三组对棱长分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2967337e3fcb228dded64ab0c41a17e0.png)
(2)若四面体ABCD每组对棱长分别相等,求证:该四面体的四个面都是锐角三角形.
您最近一年使用:0次
21-22高一下·浙江·期中
名校
2 . 在直三棱柱
中,
,
,
,D是AB的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/3/8d8bf36c-215e-4425-a5f2-85b079e045a5.png?resizew=200)
(1)求三棱锥
的体积;
(2)求证:
∥平面
;
(3)求三棱柱
的外接球的表面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70dc2c20619a4fc12a0cfda59af5b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef01b27051dd18c0041e06406e12ef40.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/3/8d8bf36c-215e-4425-a5f2-85b079e045a5.png?resizew=200)
(1)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3a7f2b719a8ff2de7883ec2f2c27731.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc7e774e4ae40c23bf4ceed179230ca.png)
(3)求三棱柱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
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2022-09-29更新
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1450次组卷
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3卷引用:四川省眉山第一中学2022-2023学年高二上学期10月月考数学(文科)试题