如图,在正方体
中,AB=2,E,F,P,Q分别为棱
,
,
,BC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/d9a776e6-58e5-41fa-8367-6c3a870b2dcf.png?resizew=175)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
平面
.
(2)在棱
上确定一点G,使P,Q,
,G四点共面,指出G的位置即可,无需说明理由,并求四边形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/31/d9a776e6-58e5-41fa-8367-6c3a870b2dcf.png?resizew=175)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b70d05c03d14c3bd6f61746e556c1f85.png)
(2)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82f0cd7f2db3d44cd398f731670b70b1.png)
更新时间:2022-03-09 14:12:10
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,在
中,
,点
为边
的中点,
.
(1)求
;
(2)求
的面积
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8879b4ae7b07927105c922c939843e4d.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/8faedb1dcf2637dbf0be0a9d40f09384.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/14/be61f49b-0e7d-4b3c-b1fb-3e8eec1d298b.png?resizew=153)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdddaf04139a84bb1f64fc9baa414497.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/372629a8666de1e9bac3e7daadcac7b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.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】记
的内角A、B、C的对边分别为a、b、c,已知
.
(1)证明:
;
(2)若角B的平分线交AC于点D,且
,
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70298774083c0ed8fab9cbf5ba6a034c.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/428d8ba5d74557ac0660343e61b3bd8f.png)
(2)若角B的平分线交AC于点D,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d16843ba124e1569767450fa674b1326.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37f8579ee0af5c0bf270354e30e11584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次
【推荐1】记
ABC的内角A,B,C所对的边分别为a,b,c,已知
,
.
(1)求c.
(2)在下列三个条件中选择一个作为补充条件,判断
ABC是否存在?若存在,求出
ABC的面积;若不存在,说明理由.
①BC边上的中线长为
,②AB边上的中线长为
,③
ABC的周长为6.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4cba95fc7d4853a243f8e3fb20ce70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a118e37c0a8a0d8b4bd3cdc15f65de20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e899c486dc49e560fc4aca05e16835b7.png)
(1)求c.
(2)在下列三个条件中选择一个作为补充条件,判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4cba95fc7d4853a243f8e3fb20ce70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4cba95fc7d4853a243f8e3fb20ce70.png)
①BC边上的中线长为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/619096595112f0340a43b756e114dd3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4cba95fc7d4853a243f8e3fb20ce70.png)
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解答题
|
适中
(0.65)
名校
解题方法
【推荐2】已知
中,角
,
,
所对的边分别为
,
,
,且
,
.
(1)求
的外接圆半径的大小;
(2)若
,
边上的中线为
,求线段
的长及
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc8f53f6edd491df62ac6038940a169e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39372e70f5465f8cf0c5ebf7653f0e68.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d2b6015e539f0877566a05be1bf6499.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.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,在三棱锥
中,已知
,且
,
分别为
的中点,
为
的中点.
平面
;
(2)求异面直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40ee2256375b801051f097d3b591aecb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5aae6b928c589af8fff50792d29d16e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b094411c562930ff2d67b582cfd48cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c913edb9403a25b451265812e32207f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/735056c174e8dd7906257a2a50a962a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e1ef332e81b9dbaf0075a345711b02c.png)
(2)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccaee8f228ff24e7c89879bb5b999cf2.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】在四棱锥
中,
为正三角形,四边形
为等腰梯形,M为棱
的中点,且
,
.
![](https://img.xkw.com/dksih/QBM/2022/4/6/2952476951158784/2953656711028736/STEM/637914db-79cf-44cc-bb77-40ce17c0e0a9.png?resizew=164)
(1)求证:
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19d5323016483af9d1fca72486942e85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6560043276739bbd99cd5064b6182f1.png)
![](https://img.xkw.com/dksih/QBM/2022/4/6/2952476951158784/2953656711028736/STEM/637914db-79cf-44cc-bb77-40ce17c0e0a9.png?resizew=164)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ba8f7af0e091e082100c3cd7f8c487f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,直四棱柱
中,侧棱
,底面
是菱形,
,
,
为侧棱
上的动点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/da5dd9fe-09c2-44f8-bdaa-17397a8da412.png?resizew=161)
(1)求证:
;
(2)在棱
上是否存在点
,使得二面角
的大小为
?试证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/da5dd9fe-09c2-44f8-bdaa-17397a8da412.png?resizew=161)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c68263d477443994e54cea454ae5490e.png)
(2)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bf29d1e4a907cf155e00c5baaed0f11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.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,在底面为菱形的四棱锥
中,
平面
,
为
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/8/f2651297-27ef-4798-b239-c538673aeea7.png?resizew=160)
(1)求证:
平面
;
(2)若三棱锥
的体积为1,求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b96fac11d72f72c805dbddb8da72d68.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/8/f2651297-27ef-4798-b239-c538673aeea7.png?resizew=160)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30067b7b236d17af8a462f96a58d11bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba759550d6c10ffd2922b936888f3973.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次