名校
解题方法
1 . 在三棱锥
中,已知
为
中点,
平面
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/e3b397d3-f38c-43d5-b9bd-2d28aaf70929.png?resizew=167)
(1)求三棱锥
的体积;
(2)若点
分别为
的中点,求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf0ec8df0fb78180e320eaa42ba362eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ce03b310edce42191f9fa75a1c909ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01cd2bf7c88e24c91625e0f20ba2a4bb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/e3b397d3-f38c-43d5-b9bd-2d28aaf70929.png?resizew=167)
(1)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1ae536809b1161fd4e83fdc7f42be96.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6ae455e13587f20880b2642a3b1df67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
您最近一年使用:0次
名校
解题方法
2 . 如图,在正方体
中,过点
且与直线
垂直的所有面对角线的条数为___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fe734023d4e70010a6b2cc3267cb86e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/013bef1a-b1e5-454f-bbd4-fcf20b28e4b5.png?resizew=176)
您最近一年使用:0次