名校
解题方法
1 . 如图正方体
的棱长为2,
是线段
的中点,平面
过点
.
截正方体所得的截面,并简要叙述理由或作图步骤;
(2)求(1)中截面多边形的面积;
(3)平面
截正方体,把正方体分为两部分,求较小的部分与较大的部分的体积的比值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0e5eadee90c7863040cd6889ad8b4b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
(2)求(1)中截面多边形的面积;
(3)平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
您最近一年使用:0次
2024-05-04更新
|
503次组卷
|
5卷引用:四川省广安第二中学校2023-2024学年高一下学期第二次月考数学试题
四川省广安第二中学校2023-2024学年高一下学期第二次月考数学试题河北省文安县第一中学2023-2024学年高一清北班下学期3月月考数学试卷江苏省无锡市辅仁高级中学2023-2024学年高一下学期期中考试数学试题(已下线)第六章立体几何初步章末二十种常考题型归类(1)-【帮课堂】(北师大版2019必修第二册)江苏省无锡市辅仁高级中学2023-2024学年高二下学期期中考试数学试题
名校
解题方法
2 . 图形是信息传播、互通的重要的视觉语言《画法几何》是法国著名数学家蒙日的数学巨著,该书在投影的基础上,用“三视图”来表示三维空间中立体图形.其体来说.做一个几何的“三视图”,需要观测者分别从几何体正面、左面、上面三个不同角度观察,从正投影的角度作图.下图中粗实线画出的是某三棱锥的三视图,且网格纸上小正方形的边长为1,则该三棱锥的外接球的表面积为( )
![](https://img.xkw.com/dksih/QBM/2022/4/7/2953094975799296/2953733587304448/STEM/1a7ca7a8908e4a54b8f65ca0b59d6346.png?resizew=474)
![](https://img.xkw.com/dksih/QBM/2022/4/7/2953094975799296/2953733587304448/STEM/1a7ca7a8908e4a54b8f65ca0b59d6346.png?resizew=474)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2022-04-08更新
|
1475次组卷
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8卷引用:四川省遂宁市射洪中学校2022届高三下学期高考适应性考试数学(理科)试题
四川省遂宁市射洪中学校2022届高三下学期高考适应性考试数学(理科)试题四川省遂宁市射洪中学校2022届高三下学期高考适应性考试数学(文科)试题四川省2023届高考专家联测卷(三)理科数学试题河北省石家庄市2022届高三二模数学试题(已下线)理科数学-2022年高考押题预测卷01(全国甲卷)(已下线)考向25空间几何体的结构、三视图和直观图(重点)河北省河北容城中学2021-2022学年高三下学期模拟数学试题甘肃省张掖市2023届高三下学期4月联考数学(理)试题
名校
解题方法
3 .
是边长为2的正三角形,
在平面上满足
,将
沿
翻折,使点
到达
的位置,若平面
平面
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/28/a1c9460d-60ba-41b1-8df2-aa051eaa0bac.png?resizew=270)
(1)作平面
,使得
,且
,说明作图方法并证明;
(2)点
满足
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da35b5c539d7ac40137eb9f665571f53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147de24f071e316b68fd2e78e3c84545.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee6765a83140d745a6de4c85d9b6b50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9b0255047b563fb5828ba05ea63049a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1095457a1433e68cc63eebe0d0c218c2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/28/a1c9460d-60ba-41b1-8df2-aa051eaa0bac.png?resizew=270)
(1)作平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88edffc97ba3b98d5e8c9e55016fa018.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcc1653fc8447569107a484816b27a7.png)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9da932bf1051907c0433c169fef04b14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a020a0605602f738285e67689f82eb4.png)
您最近一年使用:0次
名校
解题方法
4 . 在棱长为1的正方体
中,
为底面
的中心,
是棱
上一点,且
,
,
为线段
的中点,给出下列命题:
①
,
,
,
四点共面;
②三棱锥
的体积与
的取值有关;
③当
时,
;
④当
时,过
三点的平面截正方体所得截面的面积为
.
其中正确的有______ (填写序号).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0424446817f60c18f8e4e3cc202ad99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfa920e346a3d79b7ecfa395b8e72b1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee72261f6901e62dfd0ffe547406544.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84d454c82d9e52747563d47b68099249.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/16/137312de-792b-4a5b-9b8b-846be4283e38.png?resizew=162)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
②三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9933c392d85e51aba78e72468363579b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
③当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61c1eccad7857ccae05562abaaf10d25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/558e11d700481dc414d5d073b4b88a3d.png)
④当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3cf0f585938ede9eca890a6eb326d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4aee887d79c104f7d37fafa312aef6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58edfa8a9009058dfa6c9f1b2b8c8018.png)
其中正确的有
您最近一年使用:0次
2023-10-01更新
|
255次组卷
|
3卷引用:四川省通江中学2022-2023学年高二上学期期中文科数学试题
四川省通江中学2022-2023学年高二上学期期中文科数学试题北京市日坛中学2023-2024学年高二上学期期中考试数学试题(已下线)高二数学上学期期中模拟卷01(前三章:空间向量与立体几何、直线与圆、圆锥曲线)-2023-2024学年高二数学同步精品课堂(北师大版2019选择性必修第一册)
名校
5 . 已知正方体
的棱长为2,若P是线段
上的动点(包括端点),则下列说法正确的有___________ (填写所有正确结论的编号)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/14/87d68cc7-68d8-4676-8d09-772c32209983.png?resizew=178)
①
;
②直线AP与直线BD所成角的取值范围为
;
③三棱锥
中,点
到面
的距离为定值
;
④过点P且平行于平面
的平面被正方体
截得的多边形的面积为
;
⑤若点Q在四边形
内(包括边界)运动,点F是棱
的中点,
平面
,则点
的轨迹的长度为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/14/87d68cc7-68d8-4676-8d09-772c32209983.png?resizew=178)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2ccdd87b7ea0667fb405c305c6a497a.png)
②直线AP与直线BD所成角的取值范围为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc113f7f4bfb97e441d3adb1b68bd5f6.png)
③三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/114ecab0ab272ea86979fb8cf0d1c32b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
④过点P且平行于平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
⑤若点Q在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/501ad30a38299bb5d4577ce681ca210a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83e0d886ac00c4a5c0fe764d566ec62f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
您最近一年使用:0次
名校
解题方法
6 . 在长方体
中,底面
是边长为4的正方形,
,过点
作平面
与
分别交于M,N两点,且
与平面
所成的角为
,给出下列说法:
![](https://img.xkw.com/dksih/QBM/2022/7/5/3016088399233024/3016996132487168/STEM/59a23e98b8ba4cb5a36690fa638e3342.png?resizew=255)
①异面直线
与
所成角的余弦值为
;
②
平面
;
③点B到平面
的距离为
;
④截面
面积的最小值为6.
其中正确的是__________ (请填写所有正确说法的编号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d927585a17c2e98ef7d5a9589a26ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9df7fc746f8c4801d8f2f0471ba3297e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6b86c22b670a8e9f3896f9e8883fbbb.png)
![](https://img.xkw.com/dksih/QBM/2022/7/5/3016088399233024/3016996132487168/STEM/59a23e98b8ba4cb5a36690fa638e3342.png?resizew=255)
①异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8459f5f41754890d52b74652ef1f3af1.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/896e293411e2fd0da215ff20781cb36a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4508dc6d9c91157836be679c0543cac.png)
③点B到平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b0a582c36d62d83c16425b2f54b4354.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e53a3f4fbfdc9d743be259cb8a7b6b2f.png)
④截面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e74395b07e8153a0ef0bbcb5881013f.png)
其中正确的是
您最近一年使用:0次
2022-07-06更新
|
1304次组卷
|
8卷引用:四川省达州市大竹县庙坝中学2022-2023学年高二上学期期中数学试题
名校
解题方法
7 . 如图所示,在长方体
中,
,点
是棱
上的一个动点,若平面
交棱
于点
,给出下列命题:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/27/cc4fce1e-276b-4eed-9181-b794bbb34d6d.png?resizew=184)
①四棱锥
的体积恒为定值;
②存在点
,使得
平面
;
③对于棱
上任意一点
,在棱
上均有相应的点
,使得![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
平面
;
④存在唯一的点
,使得截面四边形
的周长取得最小值.
其中真命题的是_____________ . (填写所有正确答案的序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00b378805114b83f76fcece53698a28d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dce95726804cf91de63f07b37c65da6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/252053b853152bd294a8315debd00b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbb16f7dbc4b9993c4efa0764df1d8ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6e92aadc02ae971ed29bb2db51b012f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e17230625e72d3a9c6d72ff61019ff61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/655b6a742dbacdab5aaa298007663dd4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/27/cc4fce1e-276b-4eed-9181-b794bbb34d6d.png?resizew=184)
①四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb7c649d4bbd61eaef51e529ef9b1204.png)
②存在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/252053b853152bd294a8315debd00b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29bac4ff764651106d9ab46855f20331.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7759e75f16985d39b854e45774f06a86.png)
③对于棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbb16f7dbc4b9993c4efa0764df1d8ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/252053b853152bd294a8315debd00b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4c23c66ab7d74f51cb4b79d1029fb38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afc3e8a1475b983d1a4295db0e16d4c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7003aee0b4b85f0fdd48ca9ae5826d54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85bed42b435afda8e8c47dd0da8e4a1f.png)
④存在唯一的点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/252053b853152bd294a8315debd00b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/422676748fd5d893c0e4331fee24e473.png)
其中真命题的是
您最近一年使用:0次
2022-10-07更新
|
343次组卷
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11卷引用:四川省内江市2019-2020学年高二上学期期末数学(理)试题
四川省内江市2019-2020学年高二上学期期末数学(理)试题四川省成都市第八中学校2022-2023学年高三上学期第一次摸底考试文科数学试题黑龙江省大庆市大庆实验中学2019-2020学年高三上学期期中数学(文)试题湖南省邵阳市邵东县第十中学2020届高三下学期模拟考试数学(理)试题黑龙江省鹤岗市第一中学2020-2021学年高二10月月考数学(理)试题河北省张家口市第一中学2021届高三(衔接班)上学期期中数学试题宁夏银川一中2021届高三第六次月考数学(理)试题(已下线)专题4.5 立体几何中探索性问题-玩转压轴题,进军满分之2021高考数学选择题填空题宁夏银川一中2021届高三第六次月考数学(文)试题河南省顶级名校2022-2023学年高三上学期12月摸底考试数学(文)试题(已下线)模块三 专题3 小题满分挑战练(3)(人教B)
名校
解题方法
8 . 希罗平均数(Heronianmean)是两个非负实数的一种平均,设
是两个非负实数,则它们的希罗平均数
关于希罗平均数有如下说法:
①若
则
的希罗平均数
;
②三棱台
的体积
恰好是以此三棱台的上、下底面为底面且与此三棱台等高的两个三棱柱的体积
的希罗平均数;
③已知等差数列
和等比数列
的首项均为1,且
记
为
与
的希罗平均数,则数列
的前
项和
;
④在直角
中,
,则
的希罗平均数的取值范围为
;
⑤已知正四棱锥
的底面
的内切圆
的半径为
(点
为内切圆圆心),记
若
则正四棱锥
的外接球的半径
不小于
的希罗平均数.
其中正确的有___________ (填写所有正确结论的编号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22a7a0726a3ac33110c3637cd92674ea.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c34c590f48c84fe471d1af522c343c59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91ac66fed87aa83f39c224878d1e0c06.png)
②三棱台
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a9ad711b25c36dae0c2a2cedff9954.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f46bd37096f7014e00fd079823b6c3c3.png)
③已知等差数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbb017288d4b656a5a115794355924f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c59e7c7a84a4bdb959e95536d0404ceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1a466b9a1a8bc7a50484702d326d124.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc99d52c4d23ea20f480a68b82b23298.png)
④在直角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4b85155ef02a3d4ad84819e14d0c12a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c870ef83e4e9eb140594ffdd7f5600a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f41003e232db74364578d50366c2d379.png)
⑤已知正四棱锥
![](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/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bac3d1a04dda98a6a11508d3372b020.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6e1d6c40c29815018e07d861f5a78cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1960fa68fec9bbf4779e70c80de02d0d.png)
其中正确的有
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解题方法
9 . 如图所示,在长方体ABCD﹣A1B1C1D1中,点E是棱CC1上的一个动点,若平面BED1交棱AA1于点F,给出下列命题:
![](https://img.xkw.com/dksih/QBM/2020/12/29/2624770644787200/2632237824008192/STEM/1d52280c-61b4-49b1-bec7-c590b47403c3.png?resizew=243)
①四棱锥B1﹣BED1F的体积恒为定值;
②对于棱CC1上任意一点E,在棱AD上均有相应的点G,使得CG∥平面EBD1;
③O为底面ABCD对角线AC和BD的交点,在棱DD1上存在点H,使OH∥平面EBD1;
④存在唯一的点E,使得截面四边形BED1F的周长取得最小值.
其中为真命题的是_____ .(填写所有正确答案的序号)
![](https://img.xkw.com/dksih/QBM/2020/12/29/2624770644787200/2632237824008192/STEM/1d52280c-61b4-49b1-bec7-c590b47403c3.png?resizew=243)
①四棱锥B1﹣BED1F的体积恒为定值;
②对于棱CC1上任意一点E,在棱AD上均有相应的点G,使得CG∥平面EBD1;
③O为底面ABCD对角线AC和BD的交点,在棱DD1上存在点H,使OH∥平面EBD1;
④存在唯一的点E,使得截面四边形BED1F的周长取得最小值.
其中为真命题的是
您最近一年使用:0次
解题方法
10 . 如图所示,在长方体
中,点E是棱
上的一个动点,若平面
交棱
于点F,给出下列命题:
①四棱锥
的体积恒为定值;
②对于棱
上任意一点E,在棱
上均有相应的点G,使得
平面
;
③O为底面
对角线
和
的交点,在棱
上存在点H,使
平面
;
④存在唯一的点E,使得截面四边形
的周长取得最小值.
其中为真命题的是____________________ .(填写所有正确答案的序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a83c0b8db2205a6815811aa4ff5390f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
①四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b492d99c54c1d881aa0532d918c19389.png)
②对于棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a48f3a086c6961c5ba7e121a4e60738e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba4cffe5e9a3c0f5d2e3ac65fa30587d.png)
③O为底面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a0a858194b17ae1e609ed341d75194.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba4cffe5e9a3c0f5d2e3ac65fa30587d.png)
④存在唯一的点E,使得截面四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6069dc466eec75bbeb3d5c9b51cb3a70.png)
其中为真命题的是
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/b687dca9-e9c6-4d5b-930a-bf0337ecb4c0.png?resizew=143)
您最近一年使用:0次