如图四棱柱
中,
,
,
,M为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/8be08be5-ebae-49f1-8fe8-364c81f6ec7d.png?resizew=204)
(1)证明:
平面
;
(2)若四边形
是菱形,且面
面
,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f28ca4930b132289a485903ad9f1b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/8be08be5-ebae-49f1-8fe8-364c81f6ec7d.png?resizew=204)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5865d488a9cf1181016fd2e866177cdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
(2)若四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce04b35c265cc9c48b60204bd2f718ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef6eb4cbf412b69b098716b26151fba3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fa2fb03002a3c4e58c4bf3c81a22c7a.png)
2020·安徽蚌埠·三模 查看更多[2]
更新时间:2020-05-08 09:43:35
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在直三棱柱
中,
,
,点
在
上,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/16/a732cd0c-5bd1-4e59-8a69-b5dd76025d39.png?resizew=167)
(1)证明:
平面
.
(2)已知
,平面
与平面
的夹角的余弦值为
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c1ac2e11788860424508ea9e80cf89d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9959790095c938b094ddf5953d2b7d2b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/16/a732cd0c-5bd1-4e59-8a69-b5dd76025d39.png?resizew=167)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07391ef575d28f09bc5cda0ff8130a54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5888bec948373f3854258ad80171073d.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5888bec948373f3854258ad80171073d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e9a248d1d22e1c29cfbce96b32e2206.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36d74ef32584586ec4857acd0a3f4fe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7caf5cf7af17598e879101cf25f7de9.png)
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名校
【推荐2】如图所示,在四棱锥
中,已知底面
是矩形,点
为棱
的中点.
求证:
平面
.
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffc3380658a60e5c139bc30572e0e98c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
![](https://img.xkw.com/dksih/QBM/2018/1/7/1855049213214720/1855419305091072/STEM/45a07d2aef9e4307a20c60660a3be9a9.png?resizew=140)
您最近一年使用:0次
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【推荐3】如图1所示,在等腰梯形
,
,垂足为
,将
沿
折起到
的位置,使平面
平面
,如图2所示,点
为棱
上一个动点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/25/8839dd01-9be8-436f-9d5f-5bc06914ff94.png?resizew=382)
(1)当点
为棱
中点时,求证:
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eb4e4c148b9185e09e454955eaa7312.png)
(2)求证:
平面
;
(3)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/eb9955b2bfe6c283162915770553260c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd464ecd6d8e15a06865b0af3731ad2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2689f0ce5ab3467d8214794d8acb2bd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea6349c94f5b302b548ba8d32f9544a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd8168bac8b10cad2ead420a392fdef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01ff27eea7545bb06f9472f91290c54e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/25/8839dd01-9be8-436f-9d5f-5bc06914ff94.png?resizew=382)
(1)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e60db93cd34a54c98da9ff9782656c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eb4e4c148b9185e09e454955eaa7312.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe5be9a47ac9a5d72f320a47da97bfbd.png)
(3)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e539f26ed5e0b20ff7220559324869a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/028856d5101687dd8eaf130846489cfd.png)
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1】如图甲,在直角三角形ABC中,已知
,D,E分别是AB,AC的中点.将△ADE沿DE折起,使点A到达点
的位置,且平面
平面DBCE,连接
,得到如图乙所示的四棱锥
,M为线段
上一点.
(1)证明:
平面DBCE;
(2)过B,C,M三点的平面与线段
相交于点N,直线EM与BC所成角的大小为
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b0740c0d213b10fb22feaaf51c207f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7b3e7c7845a0ec3cbac709fda131764.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/390f612b4fb72c68c2235a06efec140b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd5079c787292561044cc3c1437966a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/17/c20dd0be-4bd3-47fa-963d-7fb34f11efb1.png?resizew=325)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4890e58791814622b87c4d60ea971f54.png)
(2)过B,C,M三点的平面与线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce1b066f8869d0ff4513f7a99745125.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/957cc4ab7d44f31b1a08a2cbc4db59e6.png)
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解题方法
【推荐2】已知四棱柱
中,
,
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/92fa9749-4f9e-4633-998f-2da0f7b5c24a.png?resizew=166)
(1)判断
与
是否平行?说明理由.
(2)若面
面
,面
面
,且面
面
,判断
与面
是否垂直?说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd694ad3a4733c7c84aaa7946aeea4de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c23da6be068c0a51eaaa09d81edd112.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/92fa9749-4f9e-4633-998f-2da0f7b5c24a.png?resizew=166)
(1)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5048a0736cfe012cfc909e631e2a2969.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e7fcc7301bf4c5808c71e98f9e3d1c8.png)
(2)若面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ce7b84f8a5f45b01ab978fe3fd88ce2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab360e2782b5d1b0b26c1e1572c312af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2028d40ccd9ab63a3a2c401dc2c597e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07176d9a31f264ce4b1b75ce9b3455ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e7fcc7301bf4c5808c71e98f9e3d1c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
【推荐1】如图,在三棱柱
中,
平面
,
是等边三角形,且
为棱
的中点.
(1)证明:
平面
.
(2)若
,求平面
与平面
夹角的余弦值.
![](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/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/5/34a8b100-c6b4-4ea5-9d9a-fcf9dc7d4c15.png?resizew=125)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0186d11008c7d66c85ed0d8d2e568908.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34fc772754ba16f288b265d54c938bcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea848cd2aa3a464618020475097949fc.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,在直角梯形
中,
,
,
,E为
的中点,F在线段
上,且
.将四边形
沿
折起,使得到的四边形
所在平面与平面
垂直,M为
的中点.连
,
,
.
![](https://img.xkw.com/dksih/QBM/2020/12/10/2611323251556352/2613970489147392/STEM/d06ffddd6873494bb7bd0cdd6e9eddcc.png?resizew=547)
(1)证明:
.
(2)求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ac2eaa7083623eba037a6aff36b4db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a0b7ee5370de1a4a0cf777c785bfffe.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/6bb5f97d47fbb49fcfcdc7f5e882a80b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fe65a9d11595427706080b3e9f8d68b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8098c216e0f25128682243bfdd9dbf8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a28d6477c85c5a4ac410a884e92fbe53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a275d12b5b2e28f6810468759d168336.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bfdcf0f283004878c27a1afc4f657dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bb9aeb8992010af0a9770d196593542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://img.xkw.com/dksih/QBM/2020/12/10/2611323251556352/2613970489147392/STEM/d06ffddd6873494bb7bd0cdd6e9eddcc.png?resizew=547)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2931d9dfc8b7aa5ae7f2ce07a7ee5f93.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09b97223de9f6e8a433c068eb0a1aaaf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6a2d5480e5d8c4088fc18a600ae61e8.png)
您最近一年使用:0次
解答题-证明题
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适中
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名校
【推荐3】如图,在斜三棱柱
中,已知
为正三角形,四边形
是菱形,
,
、
分别是
,
的中点,平面
平面
.
![](https://img.xkw.com/dksih/QBM/2021/12/26/2880885843951616/2885906104885248/STEM/b0c66cbedd6748e3a9f3526624377981.png?resizew=173)
(1)求证:
平面
;
(2)求平面
与平面
夹角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc17c7b2f956334f7e79f0cfe8d6ce76.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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/2021/12/26/2880885843951616/2885906104885248/STEM/b0c66cbedd6748e3a9f3526624377981.png?resizew=173)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d26d8a9d64ad3c8cba28840b41ed7837.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce12587a7129e4a6ba2837214c6c4cdf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
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