解题方法
1 . 如图所示,四边形
为矩形,
平面
,
,
为
上的点,且
平面
.
(1)求证:
.
(2)若点
在线段
上,且满足
,则线段
上是否存在一点
,使得
平面
?若存在,求出点
的位置;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55b3581f73c778ecb0931c1ab30392ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fa3c61d6c19e187b4b824b6f5610cdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/30/09feeb4f-6390-48b5-accc-a218a206c9c0.png?resizew=153)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a48e31deb78dadacc7e128ef3eb2a054.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ff84ae2da2c81b5c7ccb7e52b40eff6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
您最近一年使用:0次
2020-03-01更新
|
328次组卷
|
2卷引用:湖北省黄冈市黄州中学(黄冈外校)2022-2023学年高一实验朝阳班下学期第六次阶段性测试数学试题
名校
解题方法
2 . 如图:正三棱柱
中
,
,点P在平面
中,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7201faa561aef62a788812483fa1eb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/60f77cf3-ff13-45e3-8338-685b0b57633e.png?resizew=125)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1bb20ec923649b64b3a1a40b61c0360.png)
(2)求三棱锥
的体积
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/462b1c65b1b233ab98a90c164c0968c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7201faa561aef62a788812483fa1eb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/60f77cf3-ff13-45e3-8338-685b0b57633e.png?resizew=125)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1bb20ec923649b64b3a1a40b61c0360.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9130b5a7a17763c5f51413cf912a66a4.png)
您最近一年使用:0次
名校
3 . 如图,
是边长为2的正方形,平面
平面
,且
,
是线段
的中点,过
作直线
,
是直线
上一动点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/1/d9b05464-9b86-447b-8499-e9d86c74114f.png?resizew=186)
(1)求证:
;
(2)若直线
上存在唯一一点
使得直线
与平面
垂直,求此时二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3abb27f8d654064a92f9d7a11e586ab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5a5594708b3d94026c639aff4446b4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d620f242099d9e5e3225115c80d9bfa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/1/d9b05464-9b86-447b-8499-e9d86c74114f.png?resizew=186)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75f4a6920a0dc269d5d1781e87fe84f1.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cad4595d5352b2884568a59d8d766a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13754079766bc275a409f85d5de58aa9.png)
您最近一年使用:0次
2019-10-29更新
|
628次组卷
|
6卷引用:2020届湖北省黄冈中学高三下学期2月月考数学(理)试题
名校
4 . 如图,直三棱柱
,点M是棱
,上不同于
的动点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/879d648d-aa19-4440-b19f-b69a6b4e5736.png?resizew=135)
(I)证明:
;
(Ⅱ)若
,判断点M的位置并求出此时平面
把此棱柱分成的两部分几何体的体积之比.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf07e06e65aa75843068a69e966ab8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923f4610ef5693634afd611217b16aff.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/879d648d-aa19-4440-b19f-b69a6b4e5736.png?resizew=135)
(I)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eb2309d4f3e1154a2b929dff6b5e949.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5bb651de94f5da87df67d22aee4e8eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e67d36d29ac86703724d98da567659ec.png)
您最近一年使用:0次
2019-01-21更新
|
633次组卷
|
3卷引用:2019届湖北省黄冈中学高三适应性考试数学(文)试题
解题方法
5 . 如图,在直三棱柱
中,
,
,
,
分别为棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/9508bd8c-5b44-43c5-b3e5-e2e6cbac02ca.png?resizew=180)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
平面
;
(2)若异面直线
与
所成角为
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36cf3bff56a7f4ab6c0008e90823025d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33fa098867b1d6e1aeaebe22871821fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f02795ff1af51fb0672800ceb02e7893.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5dd68e298b39454c148c7a8d951f9b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/279cce34dd995fd1c54a7629fb16c6cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4994f75d9a4056bf04228170e27a2658.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/9508bd8c-5b44-43c5-b3e5-e2e6cbac02ca.png?resizew=180)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb31ef428bd9de9bc875b343feded3c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3f84d1ed2ff6f93bf229c738c58c15c.png)
(2)若异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e17230625e72d3a9c6d72ff61019ff61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8152cb36f666908ce1a748d9f17709dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ec1ac46e3ad9d11e07fddb913c53efa.png)
您最近一年使用:0次
2018-07-11更新
|
859次组卷
|
2卷引用:【全国市级联考】湖北省黄冈市2018年春季高一期末考试文科数学试题
6 . 如图,在Rt
中,
,点
、
分别在线段
、
上,且
,将
沿
折起到
的位置,使得二面角
的大小为
.
(1)求证:
;
(2)当点
为线段
的靠近
点的三等分点时,求
与平面
所成角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1baa1c07becd03537beeb09a31745cf5.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13bd9e8b54864ca44115d24a5aeeb83c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f201a40fedca4ad14db193f4db2127e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f1c4ed7451103f0cbf14bb9ae219b43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e51c49eed6d720f2dc30cf1a79721bfd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/260200d547998bcac50a4a491382e7f4.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a4a6a1e70241d600bc6c104313eac61.png)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2018/3/14/1901807738150912/1902197858361344/STEM/fef8f437c8f148e8a508e66d289256ae.png?resizew=16)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d246f9eceab371ebf47a47c2f11a4ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://img.xkw.com/dksih/QBM/2018/3/14/1901807738150912/1902197858361344/STEM/45d68d0767d340ac9d9d680dddac3f5b.png?resizew=419)
您最近一年使用:0次
7 . 如图,在
中,
,点
、
分别在线段
、
上,且
,将
沿
折起到
的位置,使得二面角
的大小为
.
(Ⅰ)求证:
;
(Ⅱ)当点
为线段
的靠近
点的三等分点时,求四棱锥
的侧面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a7845fd89477ecc808e5519317fff78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1baa1c07becd03537beeb09a31745cf5.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13bd9e8b54864ca44115d24a5aeeb83c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f201a40fedca4ad14db193f4db2127e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f1c4ed7451103f0cbf14bb9ae219b43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e51c49eed6d720f2dc30cf1a79721bfd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/260200d547998bcac50a4a491382e7f4.png)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a4a6a1e70241d600bc6c104313eac61.png)
(Ⅱ)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8543d05c70570e6114765efaf98a10f.png)
![](https://img.xkw.com/dksih/QBM/2018/3/14/1901807704326144/1902182846529536/STEM/2be3eec443a94e979d2c9d975f35e4bb.png?resizew=279)
您最近一年使用:0次
解题方法
8 . 如图,矩形
中,
,
为边
的中点,将
沿直线
翻转成
,构成四棱锥
,若
为线段
的中点,在翻转过程中有如下4个命题:①
平面
;②存在某个位置,使
;③存在某个位置,使
;④点
在半径为
的圆周上运动,其中正确的命题个数是( )
![](https://img.xkw.com/dksih/QBM/2017/3/30/1654875852242944/1654947766968320/STEM/51e5fdec5c7f435f8a4a26045c7b76e1.png?resizew=265)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abc28e69c1ba0aac981256887f7dfa94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa2a83fed9bf4cb09d84a980452e346.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2db2b1c641b93caae9b7a82441e4ba70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1f2344b28e00a403237f7716aa38017.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657dffbd3623b705f871878fbd9df57e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2181c78134c310f746eab44b9124e63b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf93370d9638286955c65203ce50ff1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://img.xkw.com/dksih/QBM/2017/3/30/1654875852242944/1654947766968320/STEM/51e5fdec5c7f435f8a4a26045c7b76e1.png?resizew=265)
A.1个 | B.2个 | C.3个 | D.4个 |
您最近一年使用:0次
名校
9 . 在矩形
中,
,现将
沿矩形的对角线
进行翻折,在翻折的过程中,给出下列结论:
①存在某个位置,使得直线
与直线
垂直;
②存在某个位置,使得直线
与直线
垂直;
③存在某个位置,使得直线
与直线
垂直.
其中正确结论的序号是________________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d09a9a6f020159406608000cf93d4fa9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
①存在某个位置,使得直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
②存在某个位置,使得直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
③存在某个位置,使得直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
其中正确结论的序号是
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2017-02-24更新
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1055次组卷
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13卷引用:湖北省浠水县实验高级中学2017届高三数学(文)测试题(2017年1月16日)
湖北省浠水县实验高级中学2017届高三数学(文)测试题(2017年1月16日)2017届湖北省武汉市武昌区高三1月调研考试文数试卷(已下线)二轮复习 【理】专题12 空间的平行与垂直 押题专练人教A版高中数学 高三二轮(理)专题12 点、直线、平面之间的位置关系 测试人教A版 全能练习 必修2 第二章 第三节 2.3.3 直线与平面垂直的性质湖南省衡阳市第八中学2019-2020学年高一上学期第三次考试数学试题(已下线)专题8.4 直线、平面垂直的判定与性质-2021年高考数学(文)一轮复习-题型全归纳与高效训练突破(已下线)专题8.4 直线、平面垂直的判定与性质-2021年高考数学(理)一轮复习-题型全归纳与高效训练突破(已下线)专题8.5 直线、平面垂直的判定及性质 (精练)-2021年高考数学(理)一轮复习讲练测(已下线)专题8.5 直线、平面垂直的判定及性质(精练)-2021年高考数学(理)一轮复习学与练(已下线)第36讲 直线、平面垂直的判定及性质(练) — 2022年高考数学一轮复习讲练测(课标全国版)(已下线)专题8.5 直线、平面垂直的判定及其性质(练)【理】-《2020年高考一轮复习讲练测》江苏省徐州市沛县第二中学2023-2024学年高三上学期期初测试数学试题
10 . 如图,在三棱柱
中,底面
是边长为2的等比三角形,过
作平面
平行于
,交
于
点.
![](https://img.xkw.com/dksih/QBM/2016/8/18/1572984524709888/1572984530624512/STEM/f3960477e02145de95014f5a34e28a6d.png)
(1)求证:
;
(2)若四边形
是正方形,且
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f47d6a88e962cd790d2f159c021ec1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd936a2405709574af0a73543d94ad9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/2016/8/18/1572984524709888/1572984530624512/STEM/f3960477e02145de95014f5a34e28a6d.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/971cd0358b49f1661adc674801bd6ecb.png)
(2)若四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35c5aa738865bade7eb71bed5b7e4cd1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0acc78422fa848680320ebb511907fa4.png)
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