如图,在矩形
中,
,
,
是
的中点,将
沿
向上折起,使平面
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f9e5a462c0ca3b9e2c603750a3b433b.png)
![](https://img.xkw.com/dksih/QBM/2018/4/20/1928025364922368/1931135018344448/STEM/8119c471c9004b58b2c5b2f39dd09971.png?resizew=357)
(1)求证:
;
(2)求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc11331a7b2d2619b40ee6d34c3bd620.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/6a11cb104b04c4e6a1be700e81da279a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91a2712f9cc643d4983d37c9dfe880ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f9e5a462c0ca3b9e2c603750a3b433b.png)
![](https://img.xkw.com/dksih/QBM/2018/4/20/1928025364922368/1931135018344448/STEM/8119c471c9004b58b2c5b2f39dd09971.png?resizew=357)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f304789d5bcf31d9998fd4d920cd157.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5424feb7ee793897a1eda83dc90a1e.png)
更新时间:2018-04-24 19:27:09
|
相似题推荐
解答题-问答题
|
较易
(0.85)
名校
【推荐1】如图,在三棱柱中,
.
![](https://img.xkw.com/dksih/QBM/2022/5/7/2974226561007616/2978394565894144/STEM/2e274e22d2cd45adaf20454ee5fc7d26.png?resizew=250)
(1)证明:
;
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19c40292cd20811b0bb437163625f073.png)
![](https://img.xkw.com/dksih/QBM/2022/5/7/2974226561007616/2978394565894144/STEM/2e274e22d2cd45adaf20454ee5fc7d26.png?resizew=250)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba985fb50a9078a839b66bf1d1eadea9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78d0df143a810bce6c37c2ff5ace243c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0218542daefa15910d5111b27e71f5b3.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
名校
解题方法
【推荐2】如图,直三棱柱
中,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/14/1b60ef43-230b-4005-9ea6-86d6d8ba69c9.png?resizew=132)
(1)证明:
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65b3fe18de580bcb288004e1c30b54d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf9ad150cb1e4cd8977d4cc3d99be17c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/14/1b60ef43-230b-4005-9ea6-86d6d8ba69c9.png?resizew=132)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9272bb1ab5b0bfc88be8c89a52db112e.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aa58d518fe175f71265a2e405f1d253.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
解题方法
【推荐1】如图,在四棱锥
中,底面
是直角梯形,
,平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/8099f006-7d9c-4242-ae7e-72775e854ade.png?resizew=150)
(1)证明:平面
平面
;
(2)求直线
与平面
夹角的正弦值.
![](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/1ee1c0e1894891a82c6fd7816f8fe220.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/28/8099f006-7d9c-4242-ae7e-72775e854ade.png?resizew=150)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
解题方法
【推荐2】如图,斜三棱柱
的底面是直角三角形,
,点
在底面ABC内的射影恰好是BC的中点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/30/dd430421-a586-4fb8-a8e3-eb020832c482.png?resizew=154)
(1)求证:平面
平面
;
(2)若斜棱柱的高为
,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/a355958abf7dc0f2eb949584cb87907b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c04b0b1fd6979d5cf1d7be8f5109186a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/30/dd430421-a586-4fb8-a8e3-eb020832c482.png?resizew=154)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61cdaadeae37736a1e6dd93fa1fe712f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9961e091f180e964a962adf6916f33c8.png)
(2)若斜棱柱的高为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd06851d747f8ccf046bc807b2523e65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b7903de4be7d5dc1175cfbf6e8da9f.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
解题方法
【推荐1】如图,在三棱锥
中,
平面
,
,
分别为
的中点.求证:
(1)
平面
;
(2)平面
平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1e4b16c2c6c9bd089da78122e9d2511.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91e1e4115d78e625e9e0f47cdade3286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cca04b2a2b61d62a809776670a60c09.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/5/1a194e43-710b-493c-a103-48f00fc8a59b.png?resizew=156)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc1f17c172d241cf98589639bc85eebe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37793a3a810e823e10c340986f55ddd.png)
(2)平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be4c65e0582b7d401f702b7e8b18106e.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
【推荐2】如图,在三棱柱
中,平面
平面
,
.
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d16867cc0fe4d229ff757b6bc44dcac7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf1cc9995c3846117daa8cf10aadf22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fd38f4fd6af2418573bcc7b67119be5.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb23540401925e0126a2f64304b78c73.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
名校
【推荐1】如图,三棱柱
,底面
是边长为2的正三角形,
,平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/f037d740-effe-4faa-aea0-f85a96b8214e.png?resizew=250)
(1)证明:
平面
;
(2)若
与平面
所成角的正弦值为
,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/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/696da912e610974f0f437876b3d34ee3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/f037d740-effe-4faa-aea0-f85a96b8214e.png?resizew=250)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d26d8a9d64ad3c8cba28840b41ed7837.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ef671ff46a372d5351b8c2f9eb26b48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3aace91caec728e174daec29a3568ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ef671ff46a372d5351b8c2f9eb26b48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
解题方法
【推荐2】如图,矩形AMND所在平面与直角梯形MBCN所在的平面垂直,MB//NC,MN⊥MB.
(2)若MC⊥CB,求证:BC⊥AC.
(2)若MC⊥CB,求证:BC⊥AC.
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
解题方法
【推荐3】如图1,山形图是两个全等的直角梯形
和
的组合图,将直角梯形
沿底边
翻折,得到图2所示的几何体.已知
,
,点
在线段
上,且
在几何体
中,解决下面问题.
平面
;
(2)若平面
平面
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10de2459bc376f9a3de90f74cc18ca7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cde387abe3ecba7cde65df9c58131b04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74a39a7453e6994a580038828513c68c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a3b8602719b3d371bc9ec6c441bb9f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31c34b18525831f3eda7bb90be0199b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7513c5dc6e1d35f76020f8f60c95669.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3547a914468b082d8d8741b974a03190.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c897a54f2e36bc4b52fba74b41c89d2d.png)
您最近一年使用:0次