如图,在边长为2的正方形
中(图1).点
是
中点,点
是
中点,将
,
,
分别沿
,
,
折起.使
,
,
三点重合于点
(图2)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/8bb447b3-9f03-4c38-a0c5-f01272d4ceb3.png?resizew=435)
(1)求证
:
(2)设
是
的中点,求直线PM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/1d013fc00972e4692499ed3d8711d5fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c771a4feb150ad9cff8d70431c97eb17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2ea13010e2399194be2a681310543e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13668f033d00acfc366f7e47949c4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7862d14a374156df8f8873d4fc59e8f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/8bb447b3-9f03-4c38-a0c5-f01272d4ceb3.png?resizew=435)
(1)求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6969b9971ceae406072933356189a897.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebce46aeb97373353179e5669365fa4a.png)
更新时间:2021-08-20 15:44:02
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,三棱柱
中,侧棱
平面
,
为等腰直角三角形,
,且
,
,
,
分别是
,
,
的中点.
平面
;
(2)设
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1baa3d0db9ad31d33c2883a6efed1dc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/fa6cb992b6faad4744f85d73a3b76dd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93f94bf6140206c527ca23425ede214d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d42e97eee705d164e6ac6de9ecd6d1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2990ef24039c6be7643cb582062503a.png)
您最近一年使用:0次
【推荐2】如图,在三棱锥
中,
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/22/6be288d5-32d4-4418-a443-0630c70e61ee.jpg?resizew=126)
(1)证明:平面
平面
.
(2)若
,点
在
上,且
,求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84505e6b8c4d7c858efe088867a6436d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4371a4e0c848f28f263b10c1ee6b61a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/22/6be288d5-32d4-4418-a443-0630c70e61ee.jpg?resizew=126)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8327483cdc94947584dd5f51f9dc8276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62ab0b9969a7537711aadc610b363f59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176385d91d5e29324fce4a932eff6a79.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,在斜三棱柱
中,
分别是
的中点.
平面
;
(2)若
,且
,求直线
与平面
所成角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed1db08240a186b4b563c0e3e3dfd99d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9cfe81171fa15f47d81ca8bd4369234.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6748d9b9948485c5ba87ca8751c6e053.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e0feac3ad1bef70d1849e6abb91bb2.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63c336cb7a3eec081f1de84c1de782db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90b92c6f2f64bb2768f518cab73483b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c15e58659e6ee4d93650e2edb6d6f7ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】在《九章算术·商功》中,将四个面都是直角三角形的三棱锥称为“鳖臑”.如图,现将一矩形
沿着对角线
将
折成
,且点
在平面
内的投影
在线段
上.已知
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/7/5c4b9662-8fee-4c84-bb04-c49943c59ea9.png?resizew=354)
(1)证明:三棱锥
为鳖臑;
(2)点
到平面
的距离;
(3)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acee03d4bb4667b6c345221b6c9b0fa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c79e56bc6f1db8f446fc5bd34a08865.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/7/5c4b9662-8fee-4c84-bb04-c49943c59ea9.png?resizew=354)
(1)证明:三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08a9ec3b527947cad9caa4537e0cb7e7.png)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02a7ba7cd0c654714c967a900513ba16.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图1,在直角梯形
中,
,
,且
.现以
为一边向梯形外作矩形
,然后沿边
将矩形
翻折,使
,如图2.
![](https://img.xkw.com/dksih/QBM/2021/4/4/2692687990177792/2694181527289856/STEM/10ba9db26ec44628b14780a014c85d49.png?resizew=516)
(1)求证:
平面
;
(2)若多面体
的体积为
,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/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0046177466c78f08d45449dc5639bf38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecc1cb55a57dde481f8dd07ab150676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecc1cb55a57dde481f8dd07ab150676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3da6e90f9c9617cd495abb57ab9b0e0.png)
![](https://img.xkw.com/dksih/QBM/2021/4/4/2692687990177792/2694181527289856/STEM/10ba9db26ec44628b14780a014c85d49.png?resizew=516)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(2)若多面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】已知四棱锥
,底面
是菱形,
是
的中点,
,点
在底面的射影
恰好在
上,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fa5aa6a6103dc78057146ba7f8ec8e4.png)
(Ⅰ)求证:平面
平面
;
(Ⅱ)如果二面角
的大小为
,求直线
与平面
所成二面角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd7a42341edbc0b01ab0769c4c02c3e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5c62f22d7afc5627fcb86599faa8e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fa5aa6a6103dc78057146ba7f8ec8e4.png)
(Ⅰ)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a03203dd5ac79dd8c6707e4340773359.png)
(Ⅱ)如果二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c911b404bbb8f8d5f1470585fa31ad97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d88591679796c52024d11c4de641bdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2017/12/14/1838342855294976/1839556594925568/STEM/a557f46d0354465f9c08812e7e6c9134.png?resizew=215)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐3】如图所示的五面体中,A1A,B1B,C1C都与底面ABC垂直,且∠ABC=120°,A1A=8,C1C=2,AB=BC=B1B=4.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/e1d48e20-51d0-4e93-98fc-cd1b888ddace.png?resizew=201)
(1)证明:B1A⊥平面A1B1C1;
(2)求直线AC1与平面CBB1所成的角的正弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/e1d48e20-51d0-4e93-98fc-cd1b888ddace.png?resizew=201)
(1)证明:B1A⊥平面A1B1C1;
(2)求直线AC1与平面CBB1所成的角的正弦值.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在三棱柱
中,
底面
,
,
是棱
上一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/24/3d8619e6-b343-425a-9e85-cd578d4e42ff.png?resizew=137)
(1)求证:
;
(2)若
,求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8bfe2553e852df73185d017c0a62fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ee8d4e3d0af61931e423d7f1d746264.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/24/3d8619e6-b343-425a-9e85-cd578d4e42ff.png?resizew=137)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/736eca86008d535f03500d32ac00cd46.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6251c7b2891a02f394f3b16fb866b9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21b47e1c873095436979db814ea9de44.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,多面体
中,平面
平面
,
,
四边形
为平行四边形.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/9878dfdf-8ce8-4b57-8b55-e3e26bc758a9.png?resizew=182)
(1)证明:
;
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01ff27eea7545bb06f9472f91290c54e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4a46fbde58e12b1edc038ae9e921722.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4611ceb2a28f7a7e4d24266d7f99b22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/9878dfdf-8ce8-4b57-8b55-e3e26bc758a9.png?resizew=182)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aeeee5f39ee6f9c3ea01ada75d63b93.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a33f4c358461db3633a818a52824b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fd680b3e2aeaba55e0b3b2486a0a3a8.png)
您最近一年使用:0次