如图四边形
为菱形,
为
与
交点,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/11/07bd2bb4-4858-4a10-9062-2b89e37e2d5a.png?resizew=240)
(1)证明:平面
平面
;
(2)若
,
,三棱锥
的体积为
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/662698361c6b3ddaf0c28a3c87be53e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/11/07bd2bb4-4858-4a10-9062-2b89e37e2d5a.png?resizew=240)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4a46fbde58e12b1edc038ae9e921722.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926584088b939200d88e64318f2d4e6c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb8fb552b9e21dbaba74d11aa747790.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aeeee5f39ee6f9c3ea01ada75d63b93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b565e518d475a50358fedff2f0bb8dec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1174142f3bba761585b6bc2653009b36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
更新时间:2019-12-13 06:37:14
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图所示,三棱锥
中,
与
都是边长为
的正三角形.
![](https://img.xkw.com/dksih/QBM/2021/12/6/2866745284509696/2868074143694848/STEM/2eb559169e5b481aba77d69d58e89068.png?resizew=198)
(1)三棱锥
体积的最大值.
(2)若
,
,
,
四点都在球
的表面上,且球
的半径为
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41e5db1d2fd912f77923e4c120a7dc19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7853371cf04731c81a7a5dfd7a53b34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/2021/12/6/2866745284509696/2868074143694848/STEM/2eb559169e5b481aba77d69d58e89068.png?resizew=198)
(1)三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41e5db1d2fd912f77923e4c120a7dc19.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047616f1d1d39bf6c3cd07cf63ef5b80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33a5d8831a9bef0f3d882d97d28e6d0e.png)
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解答题-问答题
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适中
(0.65)
解题方法
【推荐2】如图,在等腰梯形ADEF中,
,
,
,
.在矩形ABCD中,
.平面
平面ABCD.
![](https://img.xkw.com/dksih/QBM/2022/5/9/2975818312835072/2976966881525760/STEM/cee841f92594403aa5faa1c3e6801700.png?resizew=203)
(1)证明:
;
(2)求多面体ABCDEF的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/402ab8c49c4dd2aaa0ef47164c7cac00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fb55961fe96e155242d18d98e5c2261.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4901a7eda97d6a307db76c4fb196ba3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9367449a5847eade07e69f4feddcb027.png)
![](https://img.xkw.com/dksih/QBM/2022/5/9/2975818312835072/2976966881525760/STEM/cee841f92594403aa5faa1c3e6801700.png?resizew=203)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a989aa942219970ec11ccd6ab186d69b.png)
(2)求多面体ABCDEF的体积.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】已知四棱锥
,底面
是直角梯形,
,
,
底面
,
是边长为2的等边三角形,
.
![](https://img.xkw.com/dksih/QBM/2018/12/7/2091858249752576/2093854776967168/STEM/442047e0183c418185de37f6bc399c11.png?resizew=187)
(1)求证:平面
平面
;
(2)若点
为
中点,求二面角
的余弦值.
![](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/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3bbe4cdd2c154bd9a8073b0d4cecb8a.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/4201d3bead2e48cc80052b1418f23db9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f87ae7598d1c00713ce0fd91db106f1.png)
![](https://img.xkw.com/dksih/QBM/2018/12/7/2091858249752576/2093854776967168/STEM/442047e0183c418185de37f6bc399c11.png?resizew=187)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392469b357b12b998528499929366c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab5f236e0c248607721ff77b6ea8b6ee.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d8cd75efa204a890a35ea99146dfbc3.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,在三棱台
中,
平面
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/18/137aace9-2c25-4ea0-89e3-97c7b041cacc.png?resizew=168)
(1)求证:面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
平面
;
(2)求面
与面
所成二面角正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bec7357e3cd98a0815c1cdf2c7441ed7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/18/137aace9-2c25-4ea0-89e3-97c7b041cacc.png?resizew=168)
(1)求证:面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
(2)求面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
您最近一年使用:0次