1 . 如图是一个直三棱柱(以
为底面)被一平面所截得的几何体,截面为ABC.已知![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56117758504321927b7ff589b68fd839.png)
.
为AB的中点,证明:
平面
;
(2)求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56117758504321927b7ff589b68fd839.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91fdf988c4d34669aa166a3450e64ced.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa97d10469561da72b858293da6933c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a11228485e2af3df6f23d0a613f1e30.png)
您最近一年使用:0次
名校
解题方法
2 . 近些年来,三维扫描技术得到空前发展,从而催生了数字几何这一新兴学科.数字几何是传统几何和计算机科学相结合的产物.数字几何中的一个重要概念是曲率,用曲率来刻画几何体的弯曲程度.规定:多面体在顶点处的曲率等于
与多面体在该点的所有面角之和的差(多面体的面角是指多面体的面上的多边形的内角的大小,用弧度制表示),多面体在面上非顶点处的曲率均为零.由此可知,多面体的总曲率等于该多面体各顶点的曲率之和.例如:正方体在每个顶点有
个面角,每个面角是
,所以正方体在各顶点的曲率为
,故其总曲率为
.
(1)求四棱锥的总曲率;
(2)表面经过连续变形可以变为球面的多面体称为简单多面体.关于简单多面体有著名欧拉定理:设简单多面体的顶点数为
,棱数为
,面数为
,则有:
.利用此定理试证明:简单多面体的总曲率是常数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e9fdc1f8ed0ae44b54a9a2a3aca2db4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ad72d7565699d1ebb741eb0ce12bac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86d4f61c809edc290a6dc98f78edfb8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9609625b502348556ff8ba32deac8caa.png)
(1)求四棱锥的总曲率;
(2)表面经过连续变形可以变为球面的多面体称为简单多面体.关于简单多面体有著名欧拉定理:设简单多面体的顶点数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/303f53ed53db92be52facbf5154dfd08.png)
您最近一年使用:0次
2022-09-19更新
|
920次组卷
|
7卷引用:2022年浙江省温州市摇篮杯高一数学竞赛试题
2022年浙江省温州市摇篮杯高一数学竞赛试题(已下线)第01讲 空间几何体的结构、三视图和直观图与空间几何体的表面积和体积(练)(已下线)8.1 基本立体图形2(分层作业)-【上好课】2022-2023学年高一数学同步备课系列(人教A版2019必修第二册)(已下线)第五篇 向量与几何 专题21 曲率与曲率圆 微点3 曲率与曲率圆综合训练(已下线)11.2 锥体(第1课时)(七大题型)(分层练习)-2023-2024学年高二数学同步精品课堂(沪教版2020必修第三册)(已下线)FHsx1225yl158(已下线)专题14 棱柱、棱锥和棱台-《重难点题型·高分突破》(苏教版2019必修第二册)
名校
解题方法
3 . 如图,四棱锥
中,底面ABCD为矩形,平面
平面ABCD,
,
,E,F分别为AD,PB的中点.求证:
![](https://img.xkw.com/dksih/QBM/2021/12/29/2882847899779072/2920000285032448/STEM/8c22064922c74549955b4ec103b2c53f.png?resizew=242)
(1)
∥平面PCD;
(2)平面
平面PCD.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0453cfd7e92bf7746a88280b9e7b580.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62974d34de3a12418d6b700420afd1b2.png)
![](https://img.xkw.com/dksih/QBM/2021/12/29/2882847899779072/2920000285032448/STEM/8c22064922c74549955b4ec103b2c53f.png?resizew=242)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
(2)平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
您最近一年使用:0次
2022-02-19更新
|
774次组卷
|
6卷引用:安徽省太和中学2022-2023学年高二上学期数学竞赛试卷
解题方法
4 . 如图,已知三棱锥
,底面
是等腰三角形,
,
是等边三角形,
为线段
上一点,
,二面角
的大小为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/2bc588b0-d6de-4fe8-8947-622a87c96f3b.png?resizew=171)
(1)求证:
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e918b70b02a73685e3c536c7f380e2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e98a8ee55f8d77e8a669cea6c0c7547c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f479b251fdb01bae6d16abb7f2d694a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/2bc588b0-d6de-4fe8-8947-622a87c96f3b.png?resizew=171)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c583493109d50c9e4634c05e9042a9f.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
您最近一年使用:0次
名校
解题方法
5 . 在多面体
中,
,
,
,
,
,平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/5b41a840-320f-4493-a57b-c970c43693ce.png?resizew=191)
(1)证明:
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b430e98ea87209da6b3bbda34ea67c1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd7a42341edbc0b01ab0769c4c02c3e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/628501936b67eb3d91d355c32c84f5f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/5b41a840-320f-4493-a57b-c970c43693ce.png?resizew=191)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4999d4fbcbe15f78c29d518f25d317c2.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/422210c777ac0d625bbd81cc7601bf9b.png)
您最近一年使用:0次
2020-11-23更新
|
331次组卷
|
5卷引用:浙江省绍兴市上虞区2020-2021学年高二上学期竞赛数学试题A组
浙江省绍兴市上虞区2020-2021学年高二上学期竞赛数学试题A组中学生标准学术能力诊断性测试THUSSAT2021届高三诊断性测试 理科数学(一)试题(已下线)第八单元 立体几何(B卷 滚动提升检测)-2021年高考数学(理)一轮复习单元滚动双测卷安徽省阜阳市太和第一中学2020-2021学年高二上学期12月月考理科数学(奥赛班)试题安徽省阜阳市太和第一中学2020-2021学年高二(平行班)上学期12月月考理科数学试题
名校
解题方法
6 . 如图
,直角梯形
,
,将
沿
折起来,使平面
平面
.如图
,设
为
的中点,
,
的中点为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/5724be25-5478-45c0-87f3-a77dc61d8262.png?resizew=418)
(
)求证:
平面
.
(
)求平面
与平面
所成锐二面角的余弦值.
(
)在线段
上是否存在点
,使得
平面
,若存在确定点
的位置,若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a717c411ecb25464d817d7c2e807164.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb4cb0b82547733eef4343354bb7c791.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/5724be25-5478-45c0-87f3-a77dc61d8262.png?resizew=418)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ce03b310edce42191f9fa75a1c909ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df82499e4eaac32e09290faf3d2a166b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b78172568aac9805d2ea2d5f742bf80c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9cd0b0bda79a950fe6f44fc6d62740f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
您最近一年使用:0次
10-11高三·浙江宁波·期末
名校
解题方法
7 . 如图,正三棱柱
的所有棱长都为2,
为棱
上的动点,设
.
(1)若
,求证:
平面
:
(2)若二面角
为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/285373481cf3e827088cda755b03445e.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3cf0f585938ede9eca890a6eb326d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4560fa4ad459b58b723c74bd24e51ebf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e0254c84e44728749b34c08c28ab1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9bf2423499d45354dbc8377f1f04e16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/4804f764-8442-460a-9b9f-9277530f9915.png?resizew=199)
您最近一年使用:0次
2019-05-21更新
|
653次组卷
|
5卷引用:2011年辽宁省瓦房店市五校高二上学期竞赛数学文卷
8 . 如图所示的几何体中,
垂直于梯形
所在的平面,
为
的中点,
,四边形
为矩形,线段
交
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/09dbbc8d-1c79-4897-8778-2921326c7869.png?resizew=170)
(1)求证:
平面
;
(2)求二面角
的正弦值;
(3)在线段
上是否存在一点
,使得
与平面
所成角的大小为
?若存在,求出
的长;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c54c11863ae31dc12d880c44f823b32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cc5addb203f4b6985880c4cef3ddc14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5bf51c07144386bd23a422d9ceb140.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/09dbbc8d-1c79-4897-8778-2921326c7869.png?resizew=170)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c233b95865198572282d7a66ce689e94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
(3)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6ede9761b5b90f8dc137708e1ee90f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1b489c25405ce48699d4f0a62820bed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037fb348109dc2063a268b10eb925a57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632917e61f4208959686d118c7f19231.png)
您最近一年使用:0次
2019-06-05更新
|
4463次组卷
|
11卷引用:2015年全国高中数学联赛黑龙江赛区预赛试题
2015年全国高中数学联赛黑龙江赛区预赛试题2015届北京市昌平区高三上学期期末质量抽测理科数学试卷天津市新华中学2019届高三高考模拟数学(理)试题浙江省宁波市慈溪市三山高级中学等六校2019-2020学年高二上学期期中数学试题浙江省宁波市六校联考2019-2020学年上学期高二期中数学试题江苏省苏州市陆慕高级中学2019-2020学年高二下学期在线学习质量检测数学试题(已下线)数学-2020年高考数学押题预测卷03(江苏卷)《2020年高考押题预测卷》人教A版(2019) 选择性必修第一册 过关斩将 第一章 空间向量与立体几何 专题强化练3 立体几何中的存在性与探究性问题(已下线)专题03 空间向量与立体几何-立体几何中的存在性与探究性问题-2021-2022学年高二数学同步练习和分类专题教案(人教A版2019选择性必修第一册)福建省建瓯市芝华中学2021-2022学年高二上学期第一次阶段性检测数学试题安徽省蚌埠市五河致远实验学校、固镇县汉兴学校2023-2024学年高二上学期10月联考数学试题
9 . 如图,设
为正方形
所在平面外一点,点
分别在
上,且
.证明:直线
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6670479a0083dd2dfd5ad55b47b1ab6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b60ed701b319dbdf1541a17e8da003f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/784bf07e745ca00fc0f8e8f4c0343b77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83ce5b706ae738b30640c0d44174a739.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/a68b3c38-9043-4a12-82e1-053c850503e1.png?resizew=144)
您最近一年使用:0次
2018-12-28更新
|
200次组卷
|
6卷引用:数学奥林匹克高中训练题(150)
10 . 右图为一简单组合体,其底面ABCD为正方形,
平面
,
,且
="2" .
(1)求证:
平面
;
(2)求四棱锥B-CEPD的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc6b593f5b249e1a4aa013d493670bdf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac75a35a0d512cdb42d38b4b23585f5d.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c372d059202ec388960b125d4a87dc84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/564376a88fa74090de9f7694226a6184.png)
(2)求四棱锥B-CEPD的体积.
![](https://img.xkw.com/dksih/QBM/2012/6/20/1570892108587008/1570892114059264/STEM/723e12a94f90426185bbebc669674b99.png?resizew=204)
您最近一年使用:0次
2019-01-30更新
|
344次组卷
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4卷引用:广州省高州一中2009-2010学年高二学科竞赛(数学文)
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