如图,已知
是正三角形,EA,CD都垂直于平面ABC,且
,
,F是BE的中点,
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/1cd2b33c-38ca-454a-aaad-06129f6e735a.png?resizew=149)
求证:(1)
平面ABC;
(2)
平面EDB.
(3)求几何体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f36701e643b5ae1718aa5ce1f311601.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8e2a44d05b1d387150c4b359e021ffc.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/1cd2b33c-38ca-454a-aaad-06129f6e735a.png?resizew=149)
求证:(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aef11392fadd7dbccb073e416279993b.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
(3)求几何体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f7eee5e1864159d8242a206147b0c89.png)
更新时间:2019-08-01 19:45:53
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】三棱柱
中,棱
、
、
的中点分别是P、Q、O.
![](https://img.xkw.com/dksih/QBM/2020/2/16/2400373071708160/2401497155084288/STEM/fbad7b389aee4f66b5f9d65aa9eb0b16.png?resizew=210)
(1)求证:
平面
;
(2)若三棱柱
的体积为
,求三棱柱
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/2020/2/16/2400373071708160/2401497155084288/STEM/fbad7b389aee4f66b5f9d65aa9eb0b16.png?resizew=210)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72221ee5b504d596ff799c0b356aa0ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31cdd2441165a1e214037364047bc4dd.png)
(2)若三棱柱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84e4123975f257306440158659634c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edaf8b7886f784cd3f852a8ca4352700.png)
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【推荐2】如图,在三棱锥P–ABC中,PA⊥AB,PA⊥BC,AB⊥BC,PA=AB=BC=2,D为线段AC的中点,E为线段PC上一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/5ae65183-1b2f-4dc4-baf7-1783059af689.png?resizew=177)
(1)求证:PA⊥BD;
(2)当PA∥平面BDE时,求三棱锥E–BCD的体积.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/5ae65183-1b2f-4dc4-baf7-1783059af689.png?resizew=177)
(1)求证:PA⊥BD;
(2)当PA∥平面BDE时,求三棱锥E–BCD的体积.
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【推荐1】如图,已知三棱柱
中,侧棱与底面垂直,且
,
分别是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/13/044137f3-67f1-4350-928d-693b862a75f5.png?resizew=159)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
平面
;
(2)求平面
与平面
夹角的余弦值;
(3)点
在线段
上,若直线
与平面
所成角的余弦值为
时,求线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3275dc6ee54ee3f1606e7b491a6a27ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9d6e5b1970f8c445be8925e10105ebd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88a2eab2323b9e1a46d0f1c834eb7b97.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/13/044137f3-67f1-4350-928d-693b862a75f5.png?resizew=159)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f2af0a097c6c0870b0db6a9bec14e4f.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ce50ba5e349425274f05d46d120a74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(3)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22064b7c5fdc0cd58905f49cc480b4e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40aa9bd446815b9b94a3b4623ba576b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e935bb9d7b7115429edbd1e7469af65.png)
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解题方法
【推荐2】已知棱长为
的正方体
中,
分别为棱
和
的中点.
![](https://img.xkw.com/dksih/QBM/2020/6/18/2487519932588032/2488855060398080/STEM/730d877126864ea899556acb0aa4851e.png?resizew=182)
(1)证明:
平面
;
(2)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b7fa1c1d6321b28a2a2b7ffd0b27253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d470a5f9c2676243d595845b24c7ac95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://img.xkw.com/dksih/QBM/2020/6/18/2487519932588032/2488855060398080/STEM/730d877126864ea899556acb0aa4851e.png?resizew=182)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f68454096da710903e9693c7f2015.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f68454096da710903e9693c7f2015.png)
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【推荐1】如图,四棱锥
中,底面
是矩形,
平面
,
,
,点F是棱BC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/24/6dfa2f09-84ab-4ea4-83af-f50436b6edbe.jpg?resizew=199)
(1)证明:
;
(2)若PB与平面
所成的角为45,求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/24/6dfa2f09-84ab-4ea4-83af-f50436b6edbe.jpg?resizew=199)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44fcfedccc06e8537b1d681d1da2c1f3.png)
(2)若PB与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3e951f710b5592eb6a7e8360a0a7ae5.png)
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解题方法
【推荐2】如图,已知
平面
,四边形
为矩形,四边形
为直角梯形,
,
,
,
,求证:
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c800b6aabdc453e2c7e343061e9c6a78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99dfe4b6028cd0a29953bbb50c5a33b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
![](https://img.xkw.com/dksih/QBM/2020/8/13/2527219297026048/2530396505726976/STEM/9337ace92dc94460b1ae7ebbf3362f57.png?resizew=233)
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