如图所示,在三棱锥
中,
是边长为
的正三角形,
点在平面
的正投影
是
的中心.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/209333d9-47ed-479c-bf50-8efc9711a2a0.png?resizew=176)
(1)求证:
;
(2)若点
到平面
的距离为
,求此三棱锥的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/209333d9-47ed-479c-bf50-8efc9711a2a0.png?resizew=176)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bafa8c14100a4f847b41b9148954116c.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38be38165dc2307982fc57001a447c56.png)
更新时间:2021-11-13 09:38:11
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】已知空间几何体
中,
与
均为边长为2的等边三角形,
为腰长为3的等腰三角形,
,平面
平面
,平面
平面
分别为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/5168cc79-0615-4c0b-8a0a-4a344e587289.png?resizew=135)
(1)求证:平面
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7df6d51738ac1bc8b9530ea4a55745c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc4b17ce6e90cd3810a3696262e94c1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79c1acdd27cebb11e0266464b03b3afb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43323031573e640d0d18a800c91556a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd4914267aa0598458ee61b520fc4617.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/5168cc79-0615-4c0b-8a0a-4a344e587289.png?resizew=135)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f9ddce2cf23d751d1bfa34dddc6cdb0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e849f08b3543bcde7f3f7bcc557ee517.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,正三棱柱
的侧棱长和底面边长均为
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/2018/1/8/1856066903818240/1858751544729600/STEM/95511d5f98a34cb3a6413d544373109c.png?resizew=227)
(1)求证:
平面
;
(2)求证:
平面
;
(3)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/2018/1/8/1856066903818240/1858751544729600/STEM/95511d5f98a34cb3a6413d544373109c.png?resizew=227)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f96c673a2381f118ea2d3efc0bca1f3.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ebe6a446b91e73b181f9f4d56264dd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ba9e20d667d04bf3ee7f55cc795ce01.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d415dab5e8b0917752b854e1d2c64928.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图1,
是等腰直角三角形,
,
,E,F分别为
,
的中点,沿
将
折起,得到如图2所示的四棱锥
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/9a2e7e40-55fd-4c72-80b9-82f18d256433.png?resizew=302)
(1)求证:
平面
;
(2)当四棱锥
体积取最大值时:
①若G为
中点,求异面直线
与
所成角;
②在
中
交
于C,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c10d461a7c0b86a2f09c2ea17f38260e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/973111faadd18d09a51945f9689d6992.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ff39c7aa648afd1080206c8080ff79e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6cf4d6297c3e73d536feb42c9a10550.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/9a2e7e40-55fd-4c72-80b9-82f18d256433.png?resizew=302)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6c10d9d9ebc0a31e7ce29b62ec296b1.png)
(2)当四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6cf4d6297c3e73d536feb42c9a10550.png)
①若G为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db94ea06ef27a92107d4bb70a404a826.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0e57a13c665af88f326c9890072bf73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c962456e190ea0d7e6e88782aa8c161.png)
②在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6cf4d6297c3e73d536feb42c9a10550.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88212ba79ed3de23fa7130ebb6ef48a7.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,四边形
是平行四边形,
,
,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/02123b9c-141b-4278-9779-08695bae79b1.png?resizew=173)
(1)求证:
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/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81c97c0332c0510792375004aef6e0ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4519397ce1e517777092f9037e73aa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5beb1af9d2ffb7d0089dec2c1af554da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fad44bcdedd64068d66c8d342c27b41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b81ec2557e6b99351ece4d0b5f3e0a09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b27e47690ed332c573186992b6d25654.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/02123b9c-141b-4278-9779-08695bae79b1.png?resizew=173)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f09ad78d4eccd1a9c9ccd3c4af79c79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4734735213b599a9915e1ed91a5d8ce4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】三棱柱
中,平面
平面
,
,
,
,点F为棱
的中点,点E为线段
上的动点.
![](https://img.xkw.com/dksih/QBM/2020/7/9/2502366403821568/2503719401316352/STEM/be7b75eefeb646d88f4f443714e24314.png?resizew=175)
(1)求证:
;
(2)若直线
与平面
所成角的正弦值为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac4fb99967c46a3855bcf2885b448c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08c0e1740972a1ca726eb21e32637327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1418a51d0d8bb2017ba82aa415c9f5d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b83a71cff8e2ed9c2c93ed91a5d48671.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7410727e22a3287d19ca5df0666fcd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b10b969819d397711310c8dbb399ebc.png)
![](https://img.xkw.com/dksih/QBM/2020/7/9/2502366403821568/2503719401316352/STEM/be7b75eefeb646d88f4f443714e24314.png?resizew=175)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc90fee532e50d319081d571410421.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61f6eb7e9850bbf861dccaee95a05ae9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5f85ec74d7399de0e8b5b45f8dd244c.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,点
是正方形
的中心,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/a551e1e9-7d44-41f3-98d0-acca27ae5f98.png?resizew=182)
(1)证明:
平面
;
(2)若直线
与平面
所成角的正切值为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddbb52f9b226b1db3f6f9f055948bd38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c989f9f584fef670cb759e0a83923a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50f55738e17af43677d0fbd40851422a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8066f2f5e880d2217bc7f576920aaf69.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/a551e1e9-7d44-41f3-98d0-acca27ae5f98.png?resizew=182)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7a38e6c6dfde2b19b6b47f35a439a06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89c9c2c831a0552a7c934365bc49ad3f.png)
您最近一年使用:0次