在
中,
为边
上动点,将
沿
翻折至平面
平面
,当
与平面
所成角最大时,三棱锥
的外接球半径为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/096f11a1618c81f2a7027a08d5b924e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17580410bf63dba4fe164265afaac4cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3931333820859378ea6723ff3075189.png)
A.![]() | B.![]() | C.![]() | D.![]() |
更新时间:2022-12-20 18:41:05
|
相似题推荐
单选题
|
较难
(0.4)
解题方法
【推荐1】如图,矩形BDEF所在平面与正方形ABCD所在平面互相垂直,
,
,点P在线段EF上.给出下列命题:
![](https://img.xkw.com/dksih/QBM/2022/1/13/2893465864396800/2916171865915392/STEM/6e2bcee5e56643a68a33829d7c5f04c7.png?resizew=178)
①存在点P,使得直线
平面ACF;
②存在点P,使得直线
平面ACF;
③直线DP与平面ABCD所成角的正弦值的取值范围是
;
④三棱锥
的外接球被平面ACF所截得的截面面积是
.
其中所有真命题的序号( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/714cc3707bba3bfdb56e251999be8592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82773737609e65dea3c5c67099f1b10d.png)
![](https://img.xkw.com/dksih/QBM/2022/1/13/2893465864396800/2916171865915392/STEM/6e2bcee5e56643a68a33829d7c5f04c7.png?resizew=178)
①存在点P,使得直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c99cda5a272bbe32b28575fa51b9f6d.png)
②存在点P,使得直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b301c74bfd4824215e12ce4504cfec1.png)
③直线DP与平面ABCD所成角的正弦值的取值范围是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e7aec9f50619eb57d9a94fe60051cff.png)
④三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f178906e90bafd73e0ef9f89814855d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2deee4dfdf1c93a55744e332303a00b2.png)
其中所有真命题的序号( )
A.①③ | B.①④ | C.①②④ | D.①③④ |
您最近一年使用:0次
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名校
【推荐2】已知梯形
中,
,
,
,
,
是线段
的中点
将
沿
所在的直线翻折成四面体
,翻折的过程中下列选项错误的是
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a66200ae44919a57caf401a6d47737ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f976007b8d754ac3bf5793ed2fce37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a63e8a1e6411272e272c0ceee06e8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e51fc7d1b20a1ce1761714c1733f0511.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bb961bd7db3adb76af2d4cedb611bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3182db896bc2462331796e2a6108363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ba6fb5afc7fd86226985c0bd5e53b70.png)
![](https://img.xkw.com/dksih/QBM/2022/10/13/3086936201437184/3087431224401920/STEM/df144c563a014111926ba2fae4553021.png?resizew=4)
A.![]() ![]() |
B.当直线![]() ![]() ![]() ![]() |
C.四面体![]() ![]() |
D.四面体![]() ![]() |
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解题方法
【推荐1】设三棱锥
的底面是正三角形,侧棱长均相等,P是棱
上的点(不含端点),记直线
与直线
所成的角为
,直线
与平面
所成的角为
,二面角
的平面角是
则三个角
,
,
中最小的角是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6a94d59dee2d5a8f0425b64b2083825.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd4fce8e923062b9779553d6f282895b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf29d07c3751c41ab3503065a5a5052e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f435efcc7869eec21bdba1ed81dc3f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f435efcc7869eec21bdba1ed81dc3f5.png)
A.![]() | B.![]() | C.![]() | D.不能确定 |
您最近一年使用:0次
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【推荐2】如图,棱长为2的正方体
中,点P在线段
上运动,以下四个命题:
①三棱锥
的体积为定值;②
;③直线
与平面
所成角的正弦值为
;④
的最小值为
.其中真命题有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/29/4ec59a95-00bc-40fd-8324-c30468e43e5b.png?resizew=173)
①三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a80afb14665ad9cb3587c5364980e30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/763be97fe1e030b5509bda231a546001.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2eb89294b31ffdd2680b4361e8994d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/679748eab882a6be0fefd2cc300349a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e174e7e380fbe8d124ad9ef6c96ae1b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4056761b8f826eeb6ad8c9a151d3c9c.png)
A.1个 | B.2个 | C.3个 | D.4个 |
您最近一年使用:0次
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|
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名校
【推荐1】如图,
是边长为
的等边三角形,点
在
所在平面外,平面
平面
,点
是棱
的中点,点
分别在棱
上,且
,
. 现给出下列四个结论:①
平面
;②
是定值;③三棱锥
体积的最大值是
;④若三棱锥
的体积是
,则该三棱锥外接球的表面积是
.其中正确结论的个数是( )
![](https://img.xkw.com/dksih/QBM/2021/7/30/2775558110601216/2778914752757760/STEM/98f15ea6-9997-4185-ad37-3150592fd438.png?resizew=285)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.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/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89d4b113b22890bc910fa4502812f8e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5bb827adb2c31957a566704ed957c97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d14733aa8ee1b11bc861cd581156ea4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209e3b87346e057276f0692a7361e446.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2ca820a456491348e72587e4fe10bc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db8a91062cd1f6e139960b219e9eeb26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2daa8c54f9228940bdcbb91638f3e4cc.png)
![](https://img.xkw.com/dksih/QBM/2021/7/30/2775558110601216/2778914752757760/STEM/98f15ea6-9997-4185-ad37-3150592fd438.png?resizew=285)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
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【推荐2】如图,在长方形ABCD中,AB=2,BC=1,E为DC的中点,F为线段EC上(端点除外)一动点,现将△AFD沿AF折起,使平面ABD⊥平面ABCF.在平面ABD内过点D作DK⊥AB,K为垂足,设AK=t,则t的取值范围是( )
![](https://img.xkw.com/dksih/QBM/2020/1/21/2382045599326208/2383311929253888/STEM/47eb12d51dc2443da2563ea01bdafa53.png?resizew=292)
![](https://img.xkw.com/dksih/QBM/2020/1/21/2382045599326208/2383311929253888/STEM/47eb12d51dc2443da2563ea01bdafa53.png?resizew=292)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次