题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123005-29673.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123006-41834.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123006-74819.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123006-39517.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123006-51488.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123007-16111.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123007-17020.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123007-70680.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123007-71174.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123008-95994.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123007-70680.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123008-20925.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123008-88485.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123008-87092.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-97905.jpg)
(1)求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-16331.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-53081.png)
(2)求四棱锥
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-78059.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123010-65079.png)
解析
试题分析:(1)先证明
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123010-59798.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-53081.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123010-40788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-16331.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-53081.png)
(2)先求出
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123010-67727.png)
试题解析:(1)在图甲中,由
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123005-29673.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123006-41834.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123006-51488.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123007-16111.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123011-69467.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123011-55758.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123011-21986.png)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123010-59798.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-53081.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123010-40788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-16331.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123009-53081.png)
(2)∵平面
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123008-20925.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123008-88485.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123011-18040.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123012-33998.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123008-88485.png)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021123012-24928.png)
核心考点
试题【如图甲,是边长为6的等边三角形,分别为靠近的三等分点,点为边边的中点,线段交线段于点.将沿翻折,使平面平面,连接,形成如图乙所示的几何体.(1)求证:平面(2)】;主要考察你对柱锥台的表面积等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122949-18655.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122950-77344.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122950-35177.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122950-47326.jpg)
(1)证明::
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122950-88283.png)
(2)证明:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122950-27339.png)
(3)若
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122950-95701.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122951-27867.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122951-93052.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122949-18655.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122942-67308.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122942-34546.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122943-25948.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122943-26305.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122943-35143.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122943-21561.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122944-92942.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122943-25948.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122943-26305.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122933-63649.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122933-68980.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122934-91596.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122934-19715.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122934-66355.png)
A.![]() | B.![]() | C.![]() | D.![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122930-46108.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122915-48642.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122915-16391.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122915-24255.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122915-24904.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122916-27406.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122916-42225.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122916-74621.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122916-45120.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122916-19602.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122917-24166.png)
(1)直线
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122917-39837.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122915-16391.png)
(2)四面体
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021122917-33774.png)
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