1 . 如图,在四棱锥
中,
是正三角形,四边形
是菱形,
,
,点
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/22/304b4a8c-3eef-4fa8-85a9-6e021a0dc1fd.png?resizew=139)
(1)求证:
平面
;
(2)若平面
平面
,求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0923c7ceaa0ca373ee0fd09a96d084ac.png)
![](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/7e918b70b02a73685e3c536c7f380e2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b5e290c6b2c5508a3bf6117afbf7e1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/22/304b4a8c-3eef-4fa8-85a9-6e021a0dc1fd.png?resizew=139)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca6d50356a01ae13936f1bd8efa94c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0f434ade4aa62ace93040892aafd218.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/c26ca000cd3c0e285cb4acf011802041.png)
您最近一年使用:0次
2021-09-07更新
|
1447次组卷
|
3卷引用:广东省深圳科学高中2019-2020学年高一下学期期中数学试题
广东省深圳科学高中2019-2020学年高一下学期期中数学试题(已下线)第8章 立体几何初步(单元提升卷)-2021-2022学年高一数学考试满分全攻略(人教A版2019必修第二册)上海市嘉定区第二中学2021-2022学年高一下学期期末自查数学试题
名校
解题方法
2 . 为了求一个棱长为
的正四面体的体积,某同学设计如下解法.
解:构造一个棱长为1的正方体,如图1:则四面体
为棱长是
的正四面体,且有
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/16/6db5d8bf-a942-4eb1-b74e-0d41be5b6734.png?resizew=583)
(1)类似此解法,如图2,一个相对棱长都相等的四面体,其三组棱长分别为
,
,
,求此四面体的体积;
(2)对棱分别相等的四面体
中,
,
,
.求证:这个四面体的四个面都是锐角三角形;
(3)有4条长为2的线段和2条长为
的线段,用这6条线段作为棱且长度为
的线段不相邻,构成一个三棱锥,问
为何值时,构成三棱锥体积最大,最大值为多少?
[参考公式:三元均值不等式
及变形
,当且仅当
时取得等号]
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
解:构造一个棱长为1的正方体,如图1:则四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68ac02c2f91cadb1e328bc6ab9b9c491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6f878ffcff2ca25a434cbeea7d5c841.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/16/6db5d8bf-a942-4eb1-b74e-0d41be5b6734.png?resizew=583)
(1)类似此解法,如图2,一个相对棱长都相等的四面体,其三组棱长分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2967337e3fcb228dded64ab0c41a17e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50690dab38f4512eb72e18b7f86cf6f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4056761b8f826eeb6ad8c9a151d3c9c.png)
(2)对棱分别相等的四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c220eadc312101e2fb89dfe920f7b30d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7de966c316db1013defc56372fcf814e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d2530e7023b2345c651e8f53629ff1.png)
(3)有4条长为2的线段和2条长为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
[参考公式:三元均值不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ffb6b373d2e672bb2afc8de547861a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4849ff71159df2bb9099b26065d81e1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44acc0ee22dc4b7750e8be825e7c1355.png)
您最近一年使用:0次
2021-07-15更新
|
814次组卷
|
2卷引用:重庆市西南大学附属中学2020-2021学年高一下学期期末数学试题
解题方法
3 . 如图所示,在正方体
中,点
在棱
上,且
,点
、
、
分别是棱
、
、
的中点,
为线段
上一点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/13/50a39fd9-39d7-4c4c-83c4-ad632c0dbbc7.png?resizew=185)
(1)若平面
交平面
于直线
,求证:
;
(2)若直线
平面
,试作出平面
与正方体
各个面的交线,并写出作图步骤,保留作图痕迹;设平面
与棱
交于点
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fbafedc202bd0d86c4dfdece9f8f4fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f01d1dd10776b00e9df008f03f2608c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87cdc08e1c4a04a18d5ecea03393e36d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/13/50a39fd9-39d7-4c4c-83c4-ad632c0dbbc7.png?resizew=185)
(1)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7a447dc58e10adb7c8014071651e7c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b54387f870ae37f7951b253665d64f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb275e0e9a23118c8f61da15d4e3c869.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/565133e91e3ace2b2187cfc6f1db5be6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7a447dc58e10adb7c8014071651e7c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbf62b9fe96ad0b0f58c8b3ba3075ab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbf62b9fe96ad0b0f58c8b3ba3075ab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a4a7ba7546acc68f9cff46f1c53557f.png)
您最近一年使用:0次
名校
4 . 在直三棱柱
中,D,E,F分别为A1C1,AB1,BB1的中点.
![](https://img.xkw.com/dksih/QBM/2021/9/3/2800288467320832/2801518299717632/STEM/04e5ab86-e42a-4b38-b732-85084065c733.png?resizew=197)
(1)证明∶DE//平面B1BCC1;
(2)若AB=AC=AA1=2,AF⊥DE,求直三棱柱
外接球的表面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://img.xkw.com/dksih/QBM/2021/9/3/2800288467320832/2801518299717632/STEM/04e5ab86-e42a-4b38-b732-85084065c733.png?resizew=197)
(1)证明∶DE//平面B1BCC1;
(2)若AB=AC=AA1=2,AF⊥DE,求直三棱柱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
您最近一年使用:0次
2021-09-05更新
|
857次组卷
|
4卷引用:湖北省九师联盟2021-2022学年高三上学期8月开学考数学试题
5 . 棱锥是生活中最常见的空间图形之一,譬如我们熟悉的埃及金字塔,它的形状可视为一个正四棱锥.我国数学家很早就开始研究棱锥问题,公元一世纪左右成书的《九章算术》第五章中的第十二题,计算了正方锥、直方锥(阳马)、直三角锥(鳖臑)的体积,并给出了通用公式.公元三世纪中叶,数学家刘徽在给《九章算术》作的注中,运用极限思想证明了棱锥的体积公式.请你使用学过的相关知识,解决下列问题:如图,正三棱锥
中,三条侧棱SA,SB,SC两两垂直,侧棱长是3,底面
内一点P到侧面
的距离分别为x,y,z.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/11c42ecf-75a2-4e0c-94f1-c24e2f1d0cc1.png?resizew=147)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/307782c7-fe75-4f04-a03a-b35f73bbb313.png?resizew=135)
(1)求证:
;
(2)若
,试确定点P在底面
内的位置.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41e5db1d2fd912f77923e4c120a7dc19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef3d23ea0b4df6b49a03636e71cb9504.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/11c42ecf-75a2-4e0c-94f1-c24e2f1d0cc1.png?resizew=147)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/307782c7-fe75-4f04-a03a-b35f73bbb313.png?resizew=135)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55c2a362b51ffc3fdc60a15a394eeb98.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fcf59e219a162bb6611dd7e7d7b0893.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
您最近一年使用:0次
解题方法
6 . 祖暅(公元5—6世纪,祖冲之之子),是我国齐梁时代的数学家,他提出了一条原理:“幂势既同,则积不容异.”这句话的意思是:两个等高的几何体若在所有等高处的水平截面的面积相等,则这两个几何体的体积相等.如图将底面直径皆为
,高皆为
的椭半球体和已被挖去了圆锥体的圆柱体放置于同一平面
上,用平行于平面
且与
距离为
的平面截两个几何体得到
及
两截面,可以证明
总成立,若椭半球的短轴
,长半轴
,则下列结论正确的是( )
![](https://img.xkw.com/dksih/QBM/2022/2/19/2919607826079744/2924797869096960/STEM/8c870d00-2ab2-489d-b8ff-3db9dbcb9513.png?resizew=422)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18436f0e2391b0ab7537a566fc28204c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7ef0cd8fc26307d24ac98ea0556464a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/173d3e1ca62e4825252dddecbefe7b15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/009467e7d7de6caeb1eb01210ccb71ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b515965c22d2950b592c096c6e3bdfd4.png)
![](https://img.xkw.com/dksih/QBM/2022/2/19/2919607826079744/2924797869096960/STEM/8c870d00-2ab2-489d-b8ff-3db9dbcb9513.png?resizew=422)
A.椭半球体的体积为30π |
B.椭半球体的体积为15π |
C.如果![]() ![]() ![]() ![]() ![]() |
D.如果![]() ![]() ![]() ![]() ![]() |
您最近一年使用:0次
名校
解题方法
7 . 已知平面
与平面
是空间中距离为1的两平行平面,
,
,且
,
和
的夹角为
.
的体积为定值;
(2)已知
,且
,
,
,
,
均在半径为
的球面上.当
,
与平面
的夹角均为
时,求
.
![](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/f9934483d3f6ceb7fd9f6ea8a2747940.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7594c9f084163c330eb522dbc4fd9a28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/292d0b9ce587bd5df884a988c22ccba2.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/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdf2a96ad7e48a1a9f901a20825a917.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31f8f7e40ba386c0a9675896b52752d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefd06c239145a2b6ae87a955aa51414.png)
您最近一年使用:0次
2021-10-07更新
|
1208次组卷
|
3卷引用:“星云”2022届高三上学期第二次线上联考数学试题
“星云”2022届高三上学期第二次线上联考数学试题(已下线)第二章 立体几何中的计算 专题六 空间定值问题 微点6 空间定值问题综合训练【培优版】四川省成都市石室中学2024届高三下学期三诊模拟考试理科数学试卷
8 . 如图,已知四棱锥
,
且
,
,
,
,
的面积等于
,E是PD是中点.
![](https://img.xkw.com/dksih/QBM/2021/6/29/2753469786300416/2781031193870336/STEM/37dc3ed6-8a66-441e-993b-dff3af0ce8c3.png?resizew=282)
(Ⅰ)求四棱锥
体积的最大值;
(Ⅱ)若
,
.
(i)求证:
;
(ii)求直线CE与平面PBC所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef699f5dc072b853cfe700c6f1abbbae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a8751f226cdfbff4119a12c75a8df30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d768ffd5bf75080e8ff5ce6b472c0cc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/354ec8391bdd39377804ee4dab1d8f1c.png)
![](https://img.xkw.com/dksih/QBM/2021/6/29/2753469786300416/2781031193870336/STEM/37dc3ed6-8a66-441e-993b-dff3af0ce8c3.png?resizew=282)
(Ⅰ)求四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/185e2811de8461a7d5032872258bf433.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ea9995a58cbfbd0f8a5c712c2bcce4.png)
(i)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf6c62979a7aa534a191d8387a741e8.png)
(ii)求直线CE与平面PBC所成角的正弦值.
您最近一年使用:0次
2021-08-07更新
|
1174次组卷
|
2卷引用:浙江省湖州市2020-2021学年高一下学期期末数学试题
9 . 如图,四边形
是直角梯形,
∥
,
,
,
,
平面
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/db92e7e2-bfd0-43e6-b3af-226dcaeb401d.png?resizew=168)
(1)求证:直线
平面
;
(2)若三棱锥
的体积为
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.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/d262480ffb55b7617f44b63f130c154a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833cfda415649b832cc136caed392753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.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/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/db92e7e2-bfd0-43e6-b3af-226dcaeb401d.png?resizew=168)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c372d059202ec388960b125d4a87dc84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1601b174c1c0d24b6bc9fbb96c3d701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1f99a8e4053adc8bc59c19bca50ea69.png)
您最近一年使用:0次
解题方法
10 . 如图1所示,在四边形ABCD中,
,
,
,将△
沿BD折起,使得直线AB与平面BCD所成的角为45°,连接AC,得到如图2所示的三棱锥
.
![](https://img.xkw.com/dksih/QBM/2022/1/23/2900718882832384/2917896414863360/STEM/3e8996372a2d43d485da7bfd6a3c6bc4.png?resizew=258)
(1)证明:平面ABD
平面BCD;
(2)若三棱锥
中,二面角
的大小为60°,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/650c6c818df102a83ce5159e3208d01a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27b9f4b154a308c3613409cc65486644.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://img.xkw.com/dksih/QBM/2022/1/23/2900718882832384/2917896414863360/STEM/3e8996372a2d43d485da7bfd6a3c6bc4.png?resizew=258)
(1)证明:平面ABD
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f0ac3005d5ecd6d4cea0ce99a47ef3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
您最近一年使用:0次