已知正方体
中,点E,F分别是棱
,
的中点,过点
作出正方体
的截面,使得该截面平行于平面
.
![](https://img.xkw.com/dksih/QBM/2022/4/15/2958773704974336/2962432117063680/STEM/aca233f8b2b4405bb2fa66ba10396e70.png?resizew=156)
(1)作出该截面与正方体表面的交线,并说明理由;
(2)求
与该截面所在平面所成角的正弦值.
(截面:用一个平面去截一个几何体,平面与几何体的表面的交线围成的平面图形.)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
![](https://img.xkw.com/dksih/QBM/2022/4/15/2958773704974336/2962432117063680/STEM/aca233f8b2b4405bb2fa66ba10396e70.png?resizew=156)
(1)作出该截面与正方体表面的交线,并说明理由;
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fe734023d4e70010a6b2cc3267cb86e.png)
(截面:用一个平面去截一个几何体,平面与几何体的表面的交线围成的平面图形.)
更新时间:2022-04-20 21:06:28
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,已知正三棱柱
中,所有棱长均为2,点E,F分别为棱
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/12/2db17816-73a6-4e3e-91ad-8224a1c714a3.png?resizew=149)
(1)求
与平面AEF所成角的正弦值;
(2)过A、E、F三点作一个平面,则平面AEF与平面
有且只有一条公共直线:
①这一结论可以通过空间中关于平面的一条基本事实(也称为公理)得出,请写出该基本事实的内容;
②求这条公共直线在正三棱柱底面
内部的线段长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/12/2db17816-73a6-4e3e-91ad-8224a1c714a3.png?resizew=149)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce1b066f8869d0ff4513f7a99745125.png)
(2)过A、E、F三点作一个平面,则平面AEF与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
①这一结论可以通过空间中关于平面的一条基本事实(也称为公理)得出,请写出该基本事实的内容;
②求这条公共直线在正三棱柱底面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
您最近一年使用:0次
解答题-作图题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,直四棱柱
的底面
为直角梯形,
,
,
,
,
、
分别为棱
、
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/e41ff8de-2807-44bc-a978-37a601f7a5b6.png?resizew=183)
(1)在图中作出平面
与该棱柱的截面图形,并用阴影部分表示(不必写出作图过程);
(2)
为棱
的中点,求异面直线
与
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6037bba27008abc96a6dba99753549ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da9db73dad37a8a07a7ccc49101db545.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d262480ffb55b7617f44b63f130c154a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/e41ff8de-2807-44bc-a978-37a601f7a5b6.png?resizew=183)
(1)在图中作出平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dd5b5d9bed01632b26ab881deab2afa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】已知直角梯形形状如下,其中
,
,
,
.
(1)在线段CD上找出点F,将四边形
沿
翻折,形成几何体
.若无论二面角
多大,都能够使得几何体
为棱台,请指出点F的具体位置(无需给出证明过程).
(2)在(1)的条件下,若二面角
为直二面角,求棱台
的体积,并求出此时二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7972619832ab08705c12f2486aa13602.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/5/89d10d27-7a5c-4999-b048-68bb095d4ed3.png?resizew=375)
(1)在线段CD上找出点F,将四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e08c14e87a2bcf7090eab2fea73667d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc6a1a01fdb186620b7939c789fb8bf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ab64d1bfb556d9c529f867b9c83ad67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc6a1a01fdb186620b7939c789fb8bf3.png)
(2)在(1)的条件下,若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ab64d1bfb556d9c529f867b9c83ad67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc6a1a01fdb186620b7939c789fb8bf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd22fa132fa5c914b527c2781a516049.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图,平面ABCD⊥平面DBNM,且菱形ABCD与菱形DBNM全等,且∠MDB=∠DAB,G为MC的中点.求证:平面GBD∥平面AMN.
![](https://img.xkw.com/dksih/QBM/2022/5/6/2973773094920192/2974472302419968/STEM/81cd37b0a2b24b1cb7cf7f961098d417.png?resizew=213)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】已知四棱锥
中,四边形
为菱形,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aece402934a706adc736f292c5b98e0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/20/93b05c75-1cd6-48c4-bc27-308e451be8d9.png?resizew=205)
(1)求证:
是等边三角形;
(2)若
,求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e199a602a13df7c0754f88b44cfc4cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aece402934a706adc736f292c5b98e0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/20/93b05c75-1cd6-48c4-bc27-308e451be8d9.png?resizew=205)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5d48ac2a013300a8f10dc00dc148e92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d923a338dd2d2e29336b42574d38448.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,在等腰梯形
中,
,上底
,下底
,点
为下底
的中点,现将该梯形中的三角形
沿线段
折起,形成四棱锥
.
![](https://img.xkw.com/dksih/QBM/2018/1/20/1864471645831168/1865821711187968/STEM/74d50e322eb14e1b88bcd4add8c0c072.png?resizew=461)
(1)在四棱锥
中,求证:
;
(2)若平面
与平面
所成二面角的平面角为
,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/051f092cbf89536d7e8b9fbf9d49355d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833cfda415649b832cc136caed392753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9a814b70236a108be5d6e7ff271fe92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99be23ddbd80e2c75649e3d1f8594130.png)
![](https://img.xkw.com/dksih/QBM/2018/1/20/1864471645831168/1865821711187968/STEM/74d50e322eb14e1b88bcd4add8c0c072.png?resizew=461)
(1)在四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99be23ddbd80e2c75649e3d1f8594130.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/650c6c818df102a83ce5159e3208d01a.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9a814b70236a108be5d6e7ff271fe92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6bfad3f7e65188bcf7f62ea5acdbf4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39289d3709ba1e565b165c30ed981d87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】图中组合体由一个棱长为2的正方体
和一个四棱锥
组成(
平面
.
,
,
三点共线,
),
是
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/10/2f6a57d5-4bc7-4fec-880d-ff6404be234e.png?resizew=168)
(1)求证:
平面
;
(2)点
在棱
上靠近
的三等分点,求直线
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/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fb2e071d4e01107dcf7d95cbb86b415.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c76d296e1cf0e421b3969c70064f6fcd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/10/2f6a57d5-4bc7-4fec-880d-ff6404be234e.png?resizew=168)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30e2f7b22d83bef3421a4ecc7ed4a44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81bf7a859123936a07193592e089340a.png)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d4db9b82b67efe45a02fca32bfcf5dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81bf7a859123936a07193592e089340a.png)
您最近一年使用:0次