如图,在正方体
中
为
的中点.
(1)求三棱锥
的体积;
(2)若
为
的中点,求证:平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bafa7168302e524813426a0fa494c86f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/29/fb0fec78-2c4e-448f-a6d1-a8edc311c0d4.png?resizew=158)
(1)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5d90f940f5693b22ddf2e7c761887d8.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/920f9a182ba419efef8fb4a791c60fee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ef06a52945f8a26a4df410a777d79b7.png)
更新时间:2023-07-26 16:33:39
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在三棱锥
中,
为正三角形,
为棱
的中点,
,
,平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/1b56568e-cd28-4065-a671-4ca3b7e6e511.png?resizew=141)
(1)求证:
平面
;
(2)若
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ab13ef156d034b710d811e09b0be34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5002471e69d992c4d10c8255ba152e7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/1b56568e-cd28-4065-a671-4ca3b7e6e511.png?resizew=141)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e351795b12a190463b86d3cd9c84a823.png)
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解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐2】我国古代数学名著《九章算术》中记载:“刍(chú)甍(méng)者,下有袤有广,而上有袤无广.刍,草也.甍,窟盖也.”翻译为“底面有长有宽为矩形,顶部只有长没有宽为一条棱.刍甍的字面意思为茅草屋顶.”现有一个“刍甍”如图所示,四边形
为正方形,四边形
、
为两个全等的等腰梯形,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/14/4f3379ae-4f72-4536-8ea8-5534da79f7c2.png?resizew=173)
(1)设过点
且与直线
垂直的平面为平面
,且平面
与直线
、
分别交于
、
两点,求
的周长;
(2)求四面体
的体积;
(3)点
在线段
上且满足
.试问:在线段
上是否存在点
,使![](https://staticzujuan.xkw.com/quesimg/Upload/formula/360496a4f5cc8a5faca5e089ae4f9531.png)
平面
?若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/369eb8ad56da7dc1cdb7c43762be4bee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c197d8b99f2eb7477947e53461b5d548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeedb5f361a1baff6338436fff6c471d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/510b162030e04fab26e05fe268675c07.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/14/4f3379ae-4f72-4536-8ea8-5534da79f7c2.png?resizew=173)
(1)设过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.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/91a9bf6bda9363dbef5f6ff4bf6a5edf.png)
(2)求四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad3a079cfdcca9acdacecbf08f9f78cc.png)
(3)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e535514855b6b2a63dec369293d9464b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/360496a4f5cc8a5faca5e089ae4f9531.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895d6f710d5f67e1d4c7408d50d77281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc46688d8723cf2003fc25890265200.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60575e09a84a2004e9596cfc07b33e70.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,四边形
为矩形,
,且平面
平面
.
![](https://img.xkw.com/dksih/QBM/2022/1/19/2897873138909184/2901977249021952/STEM/98d1f63f-cc15-4eac-9aa3-83c2490d8697.png?resizew=171)
(1)若
,
分别是
,
的中点,求证:
平面
;
(2)若
是等边三角形,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1391573c30964b87ca3429bf67ae22aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
![](https://img.xkw.com/dksih/QBM/2022/1/19/2897873138909184/2901977249021952/STEM/98d1f63f-cc15-4eac-9aa3-83c2490d8697.png?resizew=171)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a779876cdfb2c489ad0eaed0f73e6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/422210c777ac0d625bbd81cc7601bf9b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbfa1a2af7e38d33634c462300df381f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/422210c777ac0d625bbd81cc7601bf9b.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,在直角梯形
中,
,
,
,直角梯形
通过直角梯形
以直线
为轴旋转得到,且使得平面
平面
.
为线段
的中点,
为线段
上的动点.
![](https://img.xkw.com/dksih/QBM/2018/3/29/1912173766615040/1912708131602432/STEM/b50b66acf6864bfe918a848a413f19d6.png?resizew=184)
(
)求证:
.
(
)当点
满足
时,求证:直线
平面
.
(
)当点
是线段
中点时,求直线
和平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72ad028a826740c9dc9d1fa5cac9b210.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b69596b94b869c4b820752de5f4c41b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/293cdfa41786bfd10ac7a4e92769dab0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/2018/3/29/1912173766615040/1912708131602432/STEM/b50b66acf6864bfe918a848a413f19d6.png?resizew=184)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3a5c773af90119232d95de70286a5d2.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91ba1e02c13027854cb0816c475e17ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cce9bfff622109f8992b2ed175960dcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faa23fa14f624ad8212bda55d321362f.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faa23fa14f624ad8212bda55d321362f.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】请从下面三个条件中任选一个,补充在下面的横线上,并作答.①
;②
;③点P在平面ABCD的射影在直线AD上.
如图,平面五边形PABCD中,△PAD是边长为2的等边三角形,
,
,
,将△PAD沿AD翻折成四棱锥P-ABCD,E是棱PD上的动点(端点除外),F、M分别是AB、CE的中点,且___________.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/2aef9bfc-e021-40a3-940e-2b6bb3e672e2.png?resizew=377)
(1)求证:
;
(2)当EF与平面PAD所成角最大时,求平面ACE与平面PAD所成的锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54b5169b1d6082c2e148e37202c57d70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f82a30d6b232dc4d8f35d2d6e0e0f42.png)
如图,平面五边形PABCD中,△PAD是边长为2的等边三角形,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/526908dfb46cf151b8ab1492a9d52047.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/2aef9bfc-e021-40a3-940e-2b6bb3e672e2.png?resizew=377)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52e831b14af240276a6d4ce63b132488.png)
(2)当EF与平面PAD所成角最大时,求平面ACE与平面PAD所成的锐二面角的余弦值.
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解答题-作图题
|
适中
(0.65)
名校
解题方法
【推荐2】已知正方体
中,P、Q分别为对角线BD、
上的点,且
.
的交线(保留作图痕迹),并求证:
平面
;
(2)若R是AB上的点,当
的值为多少时,能使平面
平面
?请给出证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e539f26ed5e0b20ff7220559324869a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77f9abe92f0cf2354ad65698bbc45c93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7253ffd3fc633d861810ee2e872188b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9abe6e8d1f4f1e8bdc46ddbae0cd789.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4da530384dd04ac90a025385e8b3c2f.png)
(2)若R是AB上的点,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/943d6e170279d007a4c943f684b1c3c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e8fd9020ac4827433593c1e3d503a30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4da530384dd04ac90a025385e8b3c2f.png)
您最近一年使用:0次