题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141707-86825.gif)
如图所示,在边长为12的正方形
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141707-22461.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141707-71044.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141708-15996.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141708-37759.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141708-58546.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141708-30038.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-50711.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-62535.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-29423.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-60390.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-25086.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141710-22520.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141710-77794.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-62535.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-29423.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-60390.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141710-18601.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141710-12295.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141709-50711.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141710-77794.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141711-27756.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141711-64592.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141711-41054.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141711-77399.gif)
(Ⅰ)求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-54942.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-40757.gif)
(Ⅱ)求四棱锥
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-83005.gif)
答案
(Ⅰ)证明:在正方形
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141707-22461.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-66228.gif)
所以三棱柱
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141711-41054.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141713-61905.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141713-86777.gif)
因为
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141708-58546.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141708-30038.gif)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141713-87349.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141713-66637.gif)
因为四边形
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141707-22461.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141713-18186.gif)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141714-85260.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141714-55794.gif)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-54942.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-40757.gif)
(Ⅱ)解:因为
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-54942.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-40757.gif)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141714-95011.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-83005.gif)
因为四边形
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141714-97721.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141715-26838.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141715-11007.gif)
所以梯形
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141714-97721.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141715-35481.gif)
所以四棱锥
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141712-83005.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141715-75385.gif)
解析
核心考点
试题【(本小题满分14分)如图所示,在边长为12的正方形中,点在线段上,且,,作//,分别交,于点,,作//,分别交,于点,,将该正方形沿,折叠,使得与重合,构成如图】;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/20191021/20191021141701-73928.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141701-33355.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141657-29671.gif)
科
A.![]() | B.![]() | C.![]() | D.![]() |
已知四棱锥的底面是矩形,侧棱长相等,棱锥的高为4,其俯视图如图所示.
(1)作出此四棱锥的主视图和侧视图,并在图中标出相关的数据;
(2)求该四棱锥的侧面积
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141643-76790.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141644-51082.gif)
ACD1截球O的截面面积为( )
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021141637-74529.jpg)
A.![]() | B.![]() | C.![]() | D.![]() |
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