如图,在长方体
中,
,
,
分别为
与
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/7b10279d-ff1f-4678-b254-49c376c08540.png?resizew=363)
(1)经过
,
作平面
,平面
与长方体
六个表面所截的截面可能是
边形,请根据
的不同的取值分别作出截面图形形状(每种情况找一个代表类型,例如
只需要画一种,下面给了四幅图,可以不用完,如果不够请自行增加),保留作图痕迹;
(2)若
为直线
上的一点,且
,求过
截面图形的周长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b336afb307355830e8e762e03c28048d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.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/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/7b10279d-ff1f-4678-b254-49c376c08540.png?resizew=363)
(1)经过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69a4380b6d1d3022593d5c3c9807ef23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08361173b096d18b33210a955e109f42.png)
19-20高二下·上海宝山·期中 查看更多[3]
更新时间:2020-05-07 09:08:08
|
【知识点】 判断正方体的截面形状
相似题推荐
解答题-作图题
|
适中
(0.65)
【推荐1】如图,正方体
的棱长为6,M是
的中点,点N在棱
上,且
.
所得的截面,写出作法;
(2)求(1)中所得截面的周长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7fba2c5dae5cfd8b0d687d67fe24825.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
(2)求(1)中所得截面的周长.
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐2】如图,在棱长为2的正方体
中,E,F,G分别为
,
,
的中点.
(1)过BG作该正方体的截面,使得该截面与平面
平行,写出作法,并说明理由;
(2)求直线DE与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f66fb71b75b63594ebeeeebd1963eed5.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/24/c28c4401-a0e3-4f48-972e-4eb70dd17bb3.png?resizew=167)
(1)过BG作该正方体的截面,使得该截面与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bff3ccea5989c60e51e321af3f53f54.png)
(2)求直线DE与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bff3ccea5989c60e51e321af3f53f54.png)
您最近一年使用:0次