解题方法
1 . 如图,在长方体
中,
,
,
与
交于点
,点
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/27/da8c7498-33eb-438f-8777-e2add067b3be.png?resizew=158)
(1)求证:
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b05f661421735de6c6a643f83c6ef8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/554b3b4c5ce7aca81becc07ed4903736.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/27/da8c7498-33eb-438f-8777-e2add067b3be.png?resizew=158)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0f856654f9deb4c1a04e920983278c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65277734669566578cbb7d690bb200fb.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a998bfc4636bd414b2cf1576dc24646.png)
您最近一年使用:0次
解题方法
2 . 正方体
的边长为1,
为正方形
的中心.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/16/9e1c9f04-bb84-44fe-835f-b5017374bd48.png?resizew=242)
(1)求证:直线
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/16/9e1c9f04-bb84-44fe-835f-b5017374bd48.png?resizew=242)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32adecb9a07c569ef65838c6e5bb0f8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4294ffdba16ae69fd03b13959d682aba.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/742d1ff29c39e0b4b20760bb352e76b5.png)
您最近一年使用:0次