题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-88793.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-13758.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-26631.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-93825.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-48384.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-11265.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-99108.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-52502.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-68233.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-73788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-11265.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-29951.png)
(1)求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-54818.png)
(1)确定点
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-73788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-11265.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-22991.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-96525.png)
(3)如果PA=AB=2,求三棱锥B-CDF的体积
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-73788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-63394.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-22991.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-96525.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-15236.png)
解析
试题分析:⑴证空间两直线垂直的常用方法是通过线面垂直来证明,本题中,由于直线
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-85865.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-39245.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-55224.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125811-12038.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-39245.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125811-78615.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125811-52634.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-85865.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-39245.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125811-55778.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-73788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-63394.png)
试题解析:⑴∵
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125811-72939.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-93825.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-93825.png)
其对角线
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-48384.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-11265.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125808-99108.png)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125811-10036.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125812-64420.png)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-55224.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125811-12038.png)
∵
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125812-20691.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125812-27922.png)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-54818.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125812-39155.png)
⑵当
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-73788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-63394.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125812-86384.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125813-57198.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-96525.png)
理由如下:
连结
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125813-27948.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-52502.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-68233.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-73788.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125810-63394.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125811-55778.png)
而
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125813-90142.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-96525.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125813-73830.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-96525.png)
故
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-22991.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125809-96525.png)
(3)三棱锥B-CDF的体积为
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125814-21773.png)
核心考点
试题【如图,在底面是正方形的四棱锥中,面,交于点,是中点,为上一动点.(1)求证:;(1)确定点在线段上的位置,使//平面,并说明理由.(3)如果PA=AB=2,求三】;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/20191021/20191021125757-68960.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125757-32971.jpg)
(1)求证:BB1∥平面EFM;
(2)求四面体
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125757-63378.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125743-19406.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125743-72892.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125743-20140.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125744-29459.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125744-37063.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125744-47434.png)
(1)求异面直线
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125744-54954.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125745-54014.png)
(2)求该三棱锥的体积
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125745-43040.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125734-40213.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125734-85635.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125734-40213.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125735-96192.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125735-88526.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125734-40213.png)
A.![]() | B.![]() | C.![]() | D.![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125717-30374.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125717-96530.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125717-20706.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125718-38179.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125718-21882.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125718-66974.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125718-78782.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125718-53542.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125719-96910.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125719-70958.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125719-60883.jpg)
(1)求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125719-82452.png)
(2)求三棱锥
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125720-71837.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125706-12419.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125706-73000.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125706-86212.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125706-32935.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125707-44885.jpg)
(1)求证:平面
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125707-23171.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125707-12596.png)
(2)如果三棱锥
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125707-90947.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191021/20191021125707-62687.png)
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