解题方法
1 . 已知底面为菱形的四棱锥
中,
是等边三角形,平面
平面ABCD,E,F分别是棱PC,AB上的点.
![](https://img.xkw.com/dksih/QBM/2022/1/15/2894894675337216/2895916770123776/STEM/c41c7a00-3bcb-43c5-8498-57b0846541ec.png?resizew=224)
(1)从下面①②③中选取两个作为条件,证明另一个成立;
①F是AB的中点;②E是PC的中点;③
平面PFD.(只需选择一种组合进行解答即可)
(2)若
,
,
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://img.xkw.com/dksih/QBM/2022/1/15/2894894675337216/2895916770123776/STEM/c41c7a00-3bcb-43c5-8498-57b0846541ec.png?resizew=224)
(1)从下面①②③中选取两个作为条件,证明另一个成立;
①F是AB的中点;②E是PC的中点;③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/137fcdac119eff6ac5990b6d201615df.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea4f5eec0addba78f2e0cdfb7ecc59a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fec78c2154c5972efd438a6555afaf2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1112ffa328ed486ffc5e4a605eb510e.png)
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