四棱柱
的底面是菱形,
平面
,点
是侧棱
上的点![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed37af24eb3135379c9df3524a782cbe.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/44b7e5cf-520e-41fb-ad4a-c12814c77114.png?resizew=160)
(1)证明:
平面
;
(2)若
是
的中点,求四棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18a99be053c95aefbebe7460e50df572.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eac5405933e725cc5c970237d63d511.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3071baf3a5c8677a842811b0cf26e2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e748663b134c6161ad31b4a279440cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed37af24eb3135379c9df3524a782cbe.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/44b7e5cf-520e-41fb-ad4a-c12814c77114.png?resizew=160)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f72cf82a82433d611bc30448954cef9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e748663b134c6161ad31b4a279440cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85aa93b676c35d9d3953570f279e2708.png)
更新时间:2020-01-28 23:36:19
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图1,在直角
中,
分别为
的中点,连结
,将
沿
折起,使平面
平面
,如图2所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/30/b0f0a220-bf15-4f59-b81e-12c0b1e98ad8.png?resizew=320)
(1)求证:
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29e16dea386864eafadc8363ab1efab0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3c032441543354c154ee67d744abb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/30/b0f0a220-bf15-4f59-b81e-12c0b1e98ad8.png?resizew=320)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4611ceb2a28f7a7e4d24266d7f99b22.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.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,四棱锥
的底面
是边长为2的菱形,
,
平面
,点
是棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/20/93a1be19-36a2-43da-bc88-cbf1b48a50c4.png?resizew=187)
(1)证明:
平面
;
(2)求三棱锥
的体积.
![](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/38501b76b1d5c0e0619ca506b6c52bce.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/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/20/93a1be19-36a2-43da-bc88-cbf1b48a50c4.png?resizew=187)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8c2b786c64e6a9ed2ec5670cde74f86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc46688d8723cf2003fc25890265200.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e682db81a82443f63a567eb29f4aa7bc.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,四棱柱
的底面
为矩形,
为
中点,平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/27/d7c36398-c2fd-47ec-88ab-5e6ce625c309.png?resizew=177)
(1)证明:
平面
;
(2)求二面角
的平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5e29ca242ec45e8932247be58c633a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a45953045e613b97eeee15ac188ae2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb119c89f01ba89c7f1684f75957736b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/27/d7c36398-c2fd-47ec-88ab-5e6ce625c309.png?resizew=177)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4890e58791814622b87c4d60ea971f54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/530bca33e52e5d0108885ff4e6978863.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】在三棱锥
中,
,且
.
(1)证明:
;
(2)求侧面
与底面
所成二面角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41e5db1d2fd912f77923e4c120a7dc19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc3a3374d63b22f6d259bbd8fcd2221e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb30e9912481902079b9b38a78d1a15f.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8337d3e8670a9ed0165ac853b80af3d9.png)
(2)求侧面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21665d21bbfb04410c78345de1fd15ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/2011/3/14/1570039145275392/1570039150436352/STEM/c5afcb1a85314cddb76e251e77a88645.png?resizew=177)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】如图所示的多面体中,
平面
,
平面
,
,且
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/604dad4b-343a-4189-9901-21fa6206756a.png?resizew=194)
(1)求直线
与平面
所成角的正弦值;
(2)求证:
平面
;
(3)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed04b01505bbd8a4ac0bc12e46f23bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4c5ae16a7145a28a91d45ef950a07c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5aabdde5c06a238f7623344f13755fa8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d758ff40da90d1872c246469bf281c5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86338536656046e93b53672ade9a78b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098a96d1e67d5e74d6122c8dfa63f183.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/604dad4b-343a-4189-9901-21fa6206756a.png?resizew=194)
(1)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34cf61780928291d51c7bbb08a5fcf81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad3a079cfdcca9acdacecbf08f9f78cc.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f95758f34f7ed97df0c44c49526cb779.png)
您最近一年使用:0次