如图,四边形
与四边形
均为菱形,
,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6b27bd5f1437c638082a7eec033b4c.png)
![](https://img.xkw.com/dksih/QBM/2021/1/14/2635815023411200/2638928527482880/STEM/d498f879e76f4557b1195115a51cadad.png?resizew=174)
(1)求证:平面
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f84f169e50dc59d4f7a8e1e36f5c847.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bd3ed8807db1250667c70433e1b6f7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6b27bd5f1437c638082a7eec033b4c.png)
![](https://img.xkw.com/dksih/QBM/2021/1/14/2635815023411200/2638928527482880/STEM/d498f879e76f4557b1195115a51cadad.png?resizew=174)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42ce82a4c37365f2d4dea2c4ad2e3288.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed7a8116d2f02b52c33fb7a49fc0d1ae.png)
更新时间:2021-01-18 19:36:44
|
相似题推荐
【推荐1】如图,在直三棱柱
中,
,
为
的中点,
为棱
上一点,且
.
![](https://img.xkw.com/dksih/QBM/2021/7/14/2764041649741824/2824332949667840/STEM/bab930835ca24b51b90da88d50346cb1.png?resizew=134)
(1)证明:平面
平面
.
(2)若
,
,且三棱柱
外接球的半径为
,求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b10134e7a46e6f6f7cb9d5e2371727d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adad77d896c9ac008a6832f10079ec2e.png)
![](https://img.xkw.com/dksih/QBM/2021/7/14/2764041649741824/2824332949667840/STEM/bab930835ca24b51b90da88d50346cb1.png?resizew=134)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3837007567ab66f5cbe93ea39d6b259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51d0fdc5a00ca0e857b89a7e1420df29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e20838e72faf737614d76fcee82ab6c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9539f8fb13345b449274b67bbda995db.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】在如图所示的几何体中,四边形
是正方形,
平面
,
分别为
的中点,且
.
![](https://img.xkw.com/dksih/QBM/2018/12/5/2090168545902592/2090845646569472/STEM/633f2c620f42480586ef595bebba4445.png?resizew=196)
(1)求证:平面
平面
;
(2)求证:平面
平面
;
(3)求三棱锥
与四棱锥
的体积之比.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39967d6f3aed6ce7b6643787795d451d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed0daabfbe7a5bc2ee3e4e69b1939399.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69ce1d402d300dd79718f31750ed4536.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92fafa121a627f41409284f47c4e8be1.png)
![](https://img.xkw.com/dksih/QBM/2018/12/5/2090168545902592/2090845646569472/STEM/633f2c620f42480586ef595bebba4445.png?resizew=196)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1fd975b889bfe7ddcec0de56b6f23ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67e8f933991decf3294cc5e1a02ed662.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5394d00a80a5900d7fd7d9961868bd22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/218054144a13435580cd132b9459546c.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f834efc124ae567fa8a9fbd94aee5bf5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,四棱锥
的底面
为平行四边形,
底面
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/11/e97126bb-5fc3-4c19-ae86-005933a83389.png?resizew=230)
(Ⅰ)求四面体
的表面积和体积;
(Ⅱ)若
是侧棱
上的一点,且
与底面
所成的是为
,求平面
与平面
夹角的余弦值.
![](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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d4746df85049d1651d3f6c30212a7a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e713f0ba80e87438cf6273fb00cb81a7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/11/e97126bb-5fc3-4c19-ae86-005933a83389.png?resizew=230)
(Ⅰ)求四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc33c014fcd3091ce7e549bb5f2cd41e.png)
(Ⅱ)若
![](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/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.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,在四棱锥
中,底面
是边长为
的正方形,侧面
底面
,且
,若
、
分别为
、
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/14/c5f975cb-7d7c-4963-8fc3-0f50bd5bd1da.png?resizew=168)
(1)求证:
平面
;
(2)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/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8cd71357a163b4a71b599905c67c822.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/14/c5f975cb-7d7c-4963-8fc3-0f50bd5bd1da.png?resizew=168)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/caa431d661bf9f419e8ab713dd4a3c80.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐3】如图1在正方形
中,
,
是
的中点,把
沿
折叠,使
为等边三角形,得到如图2所示的几何体.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/79139306-d300-4b76-9149-038a7530789f.png?resizew=274)
(Ⅰ)证明:
;
(Ⅱ)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b027ed57b9c6f24e27ec0ae282c76efa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3da7bcea5a45eeae211f5851f12a7517.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/79139306-d300-4b76-9149-038a7530789f.png?resizew=274)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c583493109d50c9e4634c05e9042a9f.png)
(Ⅱ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
您最近一年使用:0次