问题提出:已知
,
,并且
与
完全重合在一起,将
绕点
顺时针方向旋转,且
,连接
并延长交
于点
.线段
与
有怎样的数量关系?问题探究:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/9/4bf0ece1-c15a-4608-bb47-1d0f243a4d9e.png?resizew=221)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/9/3c771e6f-6e34-4abd-9f48-5b925465c7b8.png?resizew=189)
(1)先将问题特殊化.如图2,当点
在
上时,证明:
.
思路一:要证
,因为
,所以只要证
,若能证得
,问题就容易解决了.
思路二:要证
,因为
,又易得
,所以想到构造
,则有
,若能证得
,就可以得到
.
反思:这两种思路表面看起来完全不一样,其实这两种思路的思考问题的方式是一样的,就是由已知想可知,由未知想需知.还有,这两种证明思路用到的一些基础知识也是一样的,如:等角的余角相等,等边对等角,等角对等边,顶角相等的两个等腰三角形的底角也相等,等等.
(2)再探究一般情形.如图1,当点
不在
上时,证明(1)中的结论还成立.
问题拓展:
(3)如图2,过点
作
交
的延长线于点
.若
,
,直接写出四边形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39c1b5e1f90cd17148f489e28ce1bc48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f0dd821851a38e5cbe13f63bee31fb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b96715995549e5e48494101570bb3bb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b96715995549e5e48494101570bb3bb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cd20cb6665aff8d05da3c7e31da204c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/9/4bf0ece1-c15a-4608-bb47-1d0f243a4d9e.png?resizew=221)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/9/3c771e6f-6e34-4abd-9f48-5b925465c7b8.png?resizew=189)
(1)先将问题特殊化.如图2,当点
![](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/f2e59617707e98c3441445392333b491.png)
思路一:要证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2e59617707e98c3441445392333b491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb64353c99068a7a1a8508a22f5b25b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eea506dd038bbc99de25675fc42d14ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18ec350aa6fbe606d340112f53e1ffc4.png)
思路二:要证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2e59617707e98c3441445392333b491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e08e67894f52d5e404c0531774017a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dda10216132192038ec152a9a089848c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d8302d0d250b1b9e4f92f5969bdf647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/113a991940b5ef0385b25e3a16218e0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96197c5f26220141ae88e4c960062bd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2e59617707e98c3441445392333b491.png)
反思:这两种思路表面看起来完全不一样,其实这两种思路的思考问题的方式是一样的,就是由已知想可知,由未知想需知.还有,这两种证明思路用到的一些基础知识也是一样的,如:等角的余角相等,等边对等角,等角对等边,顶角相等的两个等腰三角形的底角也相等,等等.
(2)再探究一般情形.如图1,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
问题拓展:
(3)如图2,过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f61fb14b549157473d2859f73d773fd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6abf9450abb3961db463c1203fea58ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657921f28d9ebc92f154ac16d3599b3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cf7e12dc03db7186feae41fd1751499.png)
更新时间:2022-08-29 13:07:29
|
相似题推荐
解答题-问答题
|
较难
(0.4)
名校
【推荐1】综合与实践课上,老师证同学们以“正方形的折叠”为主题开展数学活动.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/11/7a00423d-50fe-419d-8412-6772068e3e69.png?resizew=273)
(1)【操作判断】操作一:对折正方形纸片
,使
与
重合,得到折痕
,把纸片展平;操作二:在
上选一点P,沿
折叠,使点A落在矩形内部点M处,把纸片展平,连接
.当点M在
上时,写出图1中
的值:______.
(2)【迁移探究】将正方形纸片
按照“操作判断”中的方式操作,并延长
交
于点Q,连接
,改变点P在
上的位置(点P不与点A、D重合),如图2,判断
与
的数量关系,并说明理由.
(3)【拓展应用】在“迁移探究”中,已知正方形纸片
的边长为
,当
时,求
的长.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/11/7a00423d-50fe-419d-8412-6772068e3e69.png?resizew=273)
(1)【操作判断】操作一:对折正方形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a996a59b48a77397d60d6211077e18b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f94c789da26cc19eea8deb50acddb0e.png)
(2)【迁移探究】将正方形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6ede9761b5b90f8dc137708e1ee90f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95cd4848ce65d25d3bb30a725322ca8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33149bfd164e70c6743fa0c97e9a897f.png)
(3)【拓展应用】在“迁移探究”中,已知正方形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf58fc46f453aac3b33f76c8e3545a20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52c736b5c7120e1994d46857eb55a175.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
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解答题-证明题
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较难
(0.4)
【推荐2】如图1,在直角三角形纸片
中,
,
,
.
[数学活动]
将三角形纸片
进行以下操作:第一步:折叠三角形纸片
使点
与点
重合,得到折痕
,然后展开铺平;第二步:将
绕点
顺时针方向旋转得到
,点
、
的对应点分别是点
、
,直线
与边
交于点
(点
不与点
重合),与边
交于点N.
[数学思考]
(1)折痕
的长为______;
(2)在
绕点
旋转的过程中,试判断
与
的数量关系,并证明你的结论;
[数学探究]
(3)如图2,在
绕点
旋转的过程中,当直线
经过点
时,求
的长;
[问题延伸]
(4)如图3,若直角三角形纸片
的两直角边
,按上边
数学活动
的步骤操作,在点
从点
开始顺时针旋转
的过程中,设
与
的重叠部分的面积为
,求
的最小值.小明在探究这个问题的过程中发现,当旋转角为
和
时,S的值比较小,你能在小明探究的基础上,求出S的最小值吗?请直接写出答案.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4494a85de0be0b97a69348115aef8513.png)
[数学活动]
将三角形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2689f0ce5ab3467d8214794d8acb2bd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65092140faebed69b87e5a134703407c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0e57a13c665af88f326c9890072bf73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/6/42514520-1c1d-4f61-9623-f3a7bd8e2211.png?resizew=478)
[数学思考]
(1)折痕
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
(2)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2689f0ce5ab3467d8214794d8acb2bd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/907d5147cea4c9ce855074864fe54506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce6c0e9de83f2e64ae33609fc08459d.png)
[数学探究]
(3)如图2,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2689f0ce5ab3467d8214794d8acb2bd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0e57a13c665af88f326c9890072bf73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
[问题延伸]
(4)如图3,若直角三角形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a566b100fb2ebe3d208f9b6527934218.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/934abdab2cb16e0adea3442c65587bea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e908e7b7fa07b74614971966234187b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/029ad83f1a3262048cba0e650b63e929.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3c65edad25ddd666cdce0d7e5afefc9.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6b86c22b670a8e9f3896f9e8883fbbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
您最近一年使用:0次
解答题-证明题
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较难
(0.4)
【推荐1】综合与实践:
问题情境:
在数学综合与实践课上,张老师启示大家利用直线、线段以及点的运动变换进行探究活动.变换条件如下:如图 1,直线 AB,AC,BC 两两相交于 A,B,C 三点,得知△ABC是等边三角形,点 E 是直线 AC 上一动点(点 E 不与点 A,C 重合),点 F 在直线 BC上,连接 BE,EF,使 EF=BE.
(1)张老师首先提出了这样一个问题:如图 1,当E是线段 AC 的中点时,确定线段 AE与 CF 的数量关系,请你直接写出结论:AE____ CF(填“>” “<”或“=”).
提出问题:
(2)“奋斗”小组受此问题的启发,提出问题:若点E是线段 AC 上的任意一点,其他条件不变,(1)中的结论是否成立?该小组认为结论仍然成立,理由如下:如图 2,过点 E作 ED∥BC,交 AB 于点 D.(请你补充完整证明过程)
拓展延伸:
(3)“缜密”小组提出的问题是:动点E的运动位置如图3,图4所示,其他条件不变,根据题意补全图形,并判断线段AE与CF的数量关系是否发生变化? 请你选择其中一种予以证明.
,AE=1,则BF 的长为__________.(请你直接写出结果).
问题情境:
在数学综合与实践课上,张老师启示大家利用直线、线段以及点的运动变换进行探究活动.变换条件如下:如图 1,直线 AB,AC,BC 两两相交于 A,B,C 三点,得知△ABC是等边三角形,点 E 是直线 AC 上一动点(点 E 不与点 A,C 重合),点 F 在直线 BC上,连接 BE,EF,使 EF=BE.
(1)张老师首先提出了这样一个问题:如图 1,当E是线段 AC 的中点时,确定线段 AE与 CF 的数量关系,请你直接写出结论:AE____ CF(填“>” “<”或“=”).
提出问题:
(2)“奋斗”小组受此问题的启发,提出问题:若点E是线段 AC 上的任意一点,其他条件不变,(1)中的结论是否成立?该小组认为结论仍然成立,理由如下:如图 2,过点 E作 ED∥BC,交 AB 于点 D.(请你补充完整证明过程)
拓展延伸:
(3)“缜密”小组提出的问题是:动点E的运动位置如图3,图4所示,其他条件不变,根据题意补全图形,并判断线段AE与CF的数量关系是否发生变化? 请你选择其中一种予以证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
【推荐2】如图,梯形
中,
,
,
,
,
,点E为
上一点,且
,点F为
上一动点,以
为边作菱形
,且点H落在边
上,点G在梯形
的内部或边
上,设
.
(1)直接写出
的长与
的度数.
(2)在点F运动过程中,是否存在某个x的值,使得四边形
为正方形?若存在,请求出x的值;若不存在,请说明理由.
(3)若菱形
的顶点G恰好在边
上,则求出此时x的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b23b5f8eb170bde1008225a7cfbd29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6747441b260ca043446b5d472fece440.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d68a7c1620c784fc641700fa004a8ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6996aa31bf1486ced60c2249a6e6989.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f4f3ab11a8b54cf29685b1f750cb130.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/611f100dcfa7803db6eb233e2e7f2dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6052936c0efa61d0821d103cb3d46488.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/24/eec8b398-9829-410e-826e-03ed28686ea7.png?resizew=228)
(1)直接写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3702b5620dbee356a8e560c78d223ad.png)
(2)在点F运动过程中,是否存在某个x的值,使得四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/611f100dcfa7803db6eb233e2e7f2dab.png)
(3)若菱形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/611f100dcfa7803db6eb233e2e7f2dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/24/712c7a83-5705-4484-a995-7dd5130923bb.png?resizew=235)
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解答题-证明题
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较难
(0.4)
【推荐1】如图,
是⊙
的直径,
是⊙
的弦,
平分
,交⊙
于点
,过点
作直线
,交
的延长线于点
,交
的延长线于点
.
![](https://img.xkw.com/dksih/QBM/2019/3/11/2158293605130240/2159543739703296/STEM/7d4cbf70618942ed8b2bc57d718dd95c.png?resizew=190)
(1)求证:
是⊙
的切线;
(2)若
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac37366d2b54dc7d9a95ac6ddda5f3a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15b68349d796cd6364397d2bd0ea2e58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://img.xkw.com/dksih/QBM/2019/3/11/2158293605130240/2159543739703296/STEM/7d4cbf70618942ed8b2bc57d718dd95c.png?resizew=190)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf15c87ca4119396aa6af1318eaaba10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
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解答题-证明题
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较难
(0.4)
【推荐2】定义:如果梯形的一个内角等于其它三个内角中的两个内角之和,那么称这个梯形为“加和角梯形”,这个内角称为“加和角”
中,
,点E为边
上一点,四边形
为菱形,点E为边
中点,求证:梯形
为“加和角梯形”,
(2)在“加和角梯形”
中,
为“加和角”,
.
①如图2,如果
,垂足为点O,
,求梯形
的周长;
②如图3,如果
,点E为边
中点,过点E作
交边
于点F,
,点G在边
上使得
是以
为腰的等腰三角形,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1d70676406f26d339465fe3473c0c05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)在“加和角梯形”
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3981e7286d41960daf4e110c1c84e03a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
①如图2,如果
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebb72416f55bfe721092b27132ad8e80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9538281f10aa8129a3d0cc49a0370db5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
②如图3,如果
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f89deb952f57f4b3fa4887b098b7b91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/117878cbd8c00f2aabcdf62b487e2dc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed9f502a0baa323c3f9c1db0f776d503.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36e5e61804ce550636a0354e0a78a22d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
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解答题-问答题
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较难
(0.4)
名校
【推荐1】如图,在
中,
,将
绕点A逆时针旋转
,得到
,使得点B、C、D恰好在同一条直线上,求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8b3ccbed8aa44da96fbf16bb9978b48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a8f3a8b0608ec011ad95c522fd2ea4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b871a762469393cdd22f15aa49ebb8f9.png)
![](https://img.xkw.com/dksih/QBM/2020/7/22/2511431380869120/2511469189005312/STEM/61d05464b3b14240a285d23a404c4384.png?resizew=194)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】如图.已知
为等腰直角三角形,
,D、E分别为
、
上的两点,
,连接
,将
绕点E逆时针旋转
得
,连接
与
交于点M.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/19/4afdbecc-22a0-4d1c-bd7a-9715f74d4ea8.png?resizew=429)
(1)如图1,当
时,若
,求
的长;
(2)如图2,连接
,N为
的中点,连接
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f89deb952f57f4b3fa4887b098b7b91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e959e2f211cd4c6bc6ad772251241bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/19/4afdbecc-22a0-4d1c-bd7a-9715f74d4ea8.png?resizew=429)
(1)如图1,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5f43672e447170a07f44be5c5a08811.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43c5e57599c26885f7ce321e567cada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(2)如图2,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1b795a5f054242e85b105083f7aacb5.png)
您最近一年使用:0次