题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-86030.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-46176.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-46176.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-86774.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-74475.png)
(1)求平面
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-30480.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-46176.png)
(2)求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225847-85738.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-30480.png)
(3)当
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225847-75680.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225847-97059.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225847-33908.png)
解析
试题分析:(1)求二面角大小时,需先找后求,∵
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-86030.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-46176.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225848-96582.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225848-88159.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225848-39153.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225848-70155.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225849-63926.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225849-12882.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-30480.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-46176.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225849-20303.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225849-14508.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225849-10509.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-30480.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225849-10509.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-30480.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225847-85738.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-30480.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225850-33954.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225850-46336.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225850-20041.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225850-88128.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-55413.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-52994.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-55413.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-30480.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225847-85738.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225846-30480.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-72326.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-10212.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-70611.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-95740.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-72326.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-13490.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-43510.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-54936.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-89520.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-79686.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-41711.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-63996.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-10167.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-70611.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225854-27449.png)
试题解析:(1) PA⊥平面ABCD,CD⊥AD,∴PD⊥CD,故∠PDA是平面PCD与平面ABCD所成二面角的平面角,在Rt△PAD中,PA⊥AD,PA=AD,∴∠PDA=45° 3分
(2)如图,取PD中点E,连结AE,EN,又M,N分别是AB,PC的中点,∴EN∥
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225854-39676.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225854-39676.png)
(3)由
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-72326.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-10212.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-70611.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-95740.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-72326.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-13490.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-43510.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-54936.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-89520.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-79686.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-41711.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-63996.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225853-10167.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225854-97226.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225854-51358.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225855-36259.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225852-95740.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225851-72326.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225847-33908.png)
核心考点
试题【如图所示,平面,四边形是矩形,,M,N分别是AB,PC的中点,(1)求平面和平面所成二面角的大小,(2)求证:平面(3)当的长度变化时,求异面直线PC与AD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/20191020/20191020225834-31607.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225834-18579.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225834-73223.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225835-46620.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225835-25380.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225835-72412.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225835-19851.png)
(1)求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225836-85318.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225836-23415.png)
(2)求点
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225836-90238.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225836-36421.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225818-99041.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225819-19935.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225819-57444.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225819-19638.png)
(Ⅰ)证明:
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225820-62027.png)
(Ⅱ)求三棱锥
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225820-24033.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225803-91691.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225803-38588.jpg)
(I)求证:CD⊥平面PAC;
(II)求二面角A-PD-C的余弦值.
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225750-87320.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191020/20191020225751-73367.png)
(I)求证:CD⊥平面PAC;
(II)侧棱PA上是否存在点E,使得BE∥平面PCD?若存在,指出点E的位置,并证明,若不存在,请说明理由.
A.有两个面平行,其余各面都是四边形的几何体叫棱柱. |
B.有两个面平行,其余各面都是平行四边形的几何体叫棱柱. |
C.有两个面平行,其余各面都是四边形,并且每相邻两个四边形的公共边都互相平行的几何体叫棱柱. |
D.用一个平面去截棱锥,底面与截面之间的部分组成的几何体叫棱台. |
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