题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035046-24877.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035046-77980.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035046-93151.png)
①点
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035046-77980.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-81985.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-87420.png)
②直线
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-10674.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-81985.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-92871.png)
③空间四边形
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-77990.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-87420.png)
④
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-15350.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035047-49734.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035048-36034.png)
⑤二面角
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035048-48493.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035048-80119.png)
其中真命题是 。(写出所有真命题的序号)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035048-52703.png)
解析
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035049-38051.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035049-67871.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035049-45255.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035049-99060.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035049-42348.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035050-39410.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035049-67871.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035050-64062.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035050-23968.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035050-25436.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035050-24568.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035051-67579.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035051-82952.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035051-87196.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035051-96803.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035052-89818.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035052-65772.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035052-94490.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035052-14696.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035052-43753.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035052-14696.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035052-43753.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035053-87641.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035053-86681.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035053-31173.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035053-88316.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035053-79552.png)
核心考点
试题【正方体,的棱长为1,为的中点,则下列五个命题:①点到平面,的距离为②直线与平面,所成的角等于③空间四边形,在正方体六个面内形成六个射影,其面积的最小值是④与所成】;主要考察你对空间几何体的结构特征等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035036-72959.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035037-17255.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035037-75946.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035037-94096.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035037-95402.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035037-45575.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035038-79781.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035038-72936.gif)
如图所示,平面PAD⊥平面ABCD,ABCD为正方形,PA⊥AD,且PA=AD=2,E,F,G分别是线段PA,PD,CD的中点。
(1)求证:BC//平面EFG;
(2)求三棱锥E—AFG的体积。
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035032-44208.jpg)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035026-78862.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035026-89165.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035026-62415.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035027-30497.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035021-66990.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035021-23920.gif)
①
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035021-98139.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035022-35287.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035022-40227.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035022-12923.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035022-54174.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035023-41247.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035023-64775.gif)
其中正确命题的序号是( )
A.①②③ | B.②③④ | C. ①③ | D.②④ |
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035011-18656.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035011-20890.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021035011-80789.gif)
点E,F分别为棱AB,PD的中点。
(I)在现有图形中,找出与AF平行的平面,并给出证明;
(II)判断平面PCE与平面PCD是否垂直?若垂直,给出证明;若不垂直,说明理由。
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