名校
1 . 如图所示,
与
都是边长为
的正三角形,平面
平面
,
平面
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/2/f7f5244d-73fc-4113-b4cf-6f57391046a9.png?resizew=147)
(1)求证:
平面
;
(2)求平面
与平面
所成二面角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661ff55b5ebbadfb600989af3cfce2fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/781e6927e3bc512359dc8b0c11e195d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c72b92177ddfe056e6f90af4f37e64d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/077c956ac0eb05cf120e14f17413dfa2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/2/f7f5244d-73fc-4113-b4cf-6f57391046a9.png?resizew=147)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68fdb2b9d6a4a54ed1328c5b3adcf7b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f35614aff055b98b76ca262f64e629d.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af68a7bf0da4f7c6f739d2e2461ad9b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
您最近一年使用:0次
2021-08-20更新
|
548次组卷
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3卷引用:安徽省淮北市树人高级中学、萧县实验中学2020-2021学年高二上学期期中联考理科数学试题
安徽省淮北市树人高级中学、萧县实验中学2020-2021学年高二上学期期中联考理科数学试题甘肃省嘉谷关市第一中学2020-2021学年高三上学期一模考试数学(理)试题(已下线)第九章 立体几何专练15—二面角大题3-2022届高三数学一轮复习
名校
解题方法
2 . 《九章算术》是我国古代数学名著,它在几何学中的研究比西方早1000多年,在《九章算术》中,将底面为直角三角形,且侧棱垂直于底面的三棱柱称为堑堵(qian du):阳马指底面为矩形,一侧棱垂直于底面的四棱锥,鳖臑(bie nao)指四个面均为直角三角形的四面体.如图在堑堵
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/1c29406e-4c8f-4ce3-bbfd-04e55081c1ce.png?resizew=139)
(1)求证:四棱锥
为阳马;
(2)若
,
,且直线
与平面
所成角的正切值为
,求锐二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/1c29406e-4c8f-4ce3-bbfd-04e55081c1ce.png?resizew=139)
(1)求证:四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29a0c82028e1259f300facd32775a15e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39b304c67046ab1b716b6c072f8ba898.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2ead078d0c9a22439c512767bf3d4c7.png)
您最近一年使用:0次
2020-12-12更新
|
337次组卷
|
4卷引用:广东省江门市2021届高三上学期调研测试数学试题
名校
解题方法
3 . 已知某几何体的直观图和三视图如下图所示,其正视图为矩形,侧视图为等腰直角三角形,俯视图为直角梯形.
![](https://img.xkw.com/dksih/QBM/2018/4/6/1918396815851520/1919457402478592/STEM/95855c07-fe1d-4505-af6a-5b473da4de6d.png?resizew=309)
![](https://img.xkw.com/dksih/QBM/2018/4/6/1918396815851520/1919457402478592/STEM/3250d8fc-e2ea-4c84-8200-8e97dbd37d55.png?resizew=303)
(1)
为
中点,在线段
上是否存在一点
,使得
平面
?若存在,求出
的长;若不存在,请说明理由;
(2)求二面角
的余弦值.
![](https://img.xkw.com/dksih/QBM/2018/4/6/1918396815851520/1919457402478592/STEM/95855c07-fe1d-4505-af6a-5b473da4de6d.png?resizew=309)
![](https://img.xkw.com/dksih/QBM/2018/4/6/1918396815851520/1919457402478592/STEM/3250d8fc-e2ea-4c84-8200-8e97dbd37d55.png?resizew=303)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17e5e2ba78a5b1dd0f39bb65d2a0a0f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/568b3739e6cdcc146708d847092dc8e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f207d2ef4fc271a5c5fef69705dc784.png)
您最近一年使用:0次
2018-04-08更新
|
403次组卷
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2卷引用:陕西省西安市八校2018届高三上学期第一次联考数学(理)试题