名校
解题方法
1 . 如图,在三棱锥
中,平面
平面
,
为等边三角形,
,且
,E,F分别为AC,PC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/27/c686e2c5-6be9-4775-91ee-9d49f55350b7.png?resizew=183)
(1)求证:
平面
;
(2)求证:平面
平面
;
(3)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fbfcae2cecc98e2d6c16dde6d3ec1c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb4957406b21df59fdf7fa184752287b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/27/c686e2c5-6be9-4775-91ee-9d49f55350b7.png?resizew=183)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373f735f0f04d11f1951eaef1bb78b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e51838e395dfc9d9ef597d9e01f46272.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
您最近一年使用:0次
解题方法
2 . 已知a,b表示两条直线,
表示平面,若
,
,则b与
的位置关系是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa5aa846a5b7c96fe2ce665eb1ea5f0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4d6a7aec04e1d5768ef830b534460a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
A.![]() | B.![]() | C.b与![]() | D.以上都有可能 |
您最近一年使用:0次
解题方法
3 . 如图,在直三棱柱
中,D是AB的中点.
![](https://img.xkw.com/dksih/QBM/2020/3/11/2417269901877248/2417716733911040/STEM/54492ed0a0cb4c2385b1c56d62e62510.png?resizew=219)
(1)求证:
平面
;
(2)若
,
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://img.xkw.com/dksih/QBM/2020/3/11/2417269901877248/2417716733911040/STEM/54492ed0a0cb4c2385b1c56d62e62510.png?resizew=219)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f5830646a912c3a916beac4f88c116b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d695c8b31b955823b8c3d07b5d94692.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de570eefaadf8f41dc67a2a785daae82.png)
您最近一年使用:0次