三棱锥
中,底面
与侧面
均为正三角形,
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2021/1/14/2636036714627072/2638013535633408/STEM/ee32483f-aac9-49e7-8a4b-d85e8bc22466.png?resizew=238)
(1)证明:平面
平面
;
(2)
为线段
上一点,且
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea3e27f6e6d1592408508cc9fd14d480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2021/1/14/2636036714627072/2638013535633408/STEM/ee32483f-aac9-49e7-8a4b-d85e8bc22466.png?resizew=238)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a13de8cbfb0b865ea5a61e7a4ff1abe3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9cee228a9d8c0636277d10f954221d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0cd3667a5d668bce45e7c562a30e287.png)
更新时间:2021-01-17 12:35:11
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,直三棱柱
中,
的面积为
,四棱锥
的体积为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/5/b5c56dde-ebf2-4db5-97ab-fb6fc4fd7d4b.png?resizew=143)
(1)求
到平面
的距离;
(2)若
,且平面
平面
,求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e827641feb4179bca7033ed8760bf728.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bacae35b6e16a0a33c2bdc6bc07df7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c34f6658a6fa46b1597f382a3455ad04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a391005600bdd69c96750589f9adb048.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/5/b5c56dde-ebf2-4db5-97ab-fb6fc4fd7d4b.png?resizew=143)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eeed487430a5b8a330f2d0c52166521a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21dee56b9f36ba8f76fe67b76383636b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0218542daefa15910d5111b27e71f5b3.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图,在四棱锥P ABCD中,E是棱PC上一点,且2
,底面ABCD是边长为2的正方形,△PAD为正三角形,平面ABE与棱PD交于点F,平面PCD与平面PAB交于直线l,且平面PAD⊥平面ABCD.
![](https://img.xkw.com/dksih/QBM/2018/11/10/2072385142415360/2075445133524992/STEM/8f91419670f4435799837a94488ec985.png?resizew=148)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18a93934ab56bb11a3b0ab8bd01d7c30.png)
![](https://img.xkw.com/dksih/QBM/2018/11/10/2072385142415360/2075445133524992/STEM/8f91419670f4435799837a94488ec985.png?resizew=148)
(1)求证:l∥EF;
(2)求四棱锥P-ABEF的体积.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,在几何体
中,四边形
是边长为2的正方形,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/31/17fc372e-e5c6-4623-8fc0-aaf6addb1cf6.png?resizew=160)
(1)求证:平面
平面
.
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c1c122603b60b6f1a1334ddb56c3fb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0fff774b4b0087a6f304ce930d359be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e18f38545fb6d8ba32c993f60dc9a774.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1133f10924d3184380712222aea0843d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/31/17fc372e-e5c6-4623-8fc0-aaf6addb1cf6.png?resizew=160)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39282bdf319f30d7bc261e2e3ab3b1e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8768996ca9a0f2c5d9a19abbd54df.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图,在几何体
中,四边形
是边长为
的正方形,
平面
,
,点
为
的中点,四棱锥
是高为
的正四棱锥.
![](https://img.xkw.com/dksih/QBM/2021/12/30/2883681132634112/2884361130393600/STEM/65c8ae01ea45456f82247aa9d0d86400.png?resizew=191)
(1)求证:平面
平面
;
(2)求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73cbd9eb22f75ad5304d8491b314a9a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58fc6a5e71fa379d613ac1ef1cdf1048.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55c6caa0455442437177ab9b995df37b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://img.xkw.com/dksih/QBM/2021/12/30/2883681132634112/2884361130393600/STEM/65c8ae01ea45456f82247aa9d0d86400.png?resizew=191)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/677d1863ff4d8ac1604b18149d4f320f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee188333e1fa99417aede565c6a4a136.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c606f78391198b6648ba0b92b60f8cf.png)
您最近一年使用:0次