正方形ABCD和正方形AEFG的边长分别为6和2,将正方形AEFG绕点A逆时针旋转.
![](https://img.xkw.com/dksih/QBM/2022/3/3/2928278711910400/2932734160060416/STEM/22aae1d7-6037-4570-8b2d-cef59e7011cd.png?resizew=456)
(1)当旋转至图1位置时,连接BE,DG,线段BE和DG是否相等且垂直?请说明理由;
(2)在图1中,连接BD,BF,DF,请直接写出在旋转过程中
的面积最大值;
(3)在旋转过程中,当点G,E,D在同一直线上时,请求出线段BE的长.
![](https://img.xkw.com/dksih/QBM/2022/3/3/2928278711910400/2932734160060416/STEM/22aae1d7-6037-4570-8b2d-cef59e7011cd.png?resizew=456)
(1)当旋转至图1位置时,连接BE,DG,线段BE和DG是否相等且垂直?请说明理由;
(2)在图1中,连接BD,BF,DF,请直接写出在旋转过程中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7e64c953aaf341e772a5fe776fbc78a.png)
(3)在旋转过程中,当点G,E,D在同一直线上时,请求出线段BE的长.
更新时间:2022-03-09 22:05:50
|
相似题推荐
解答题-问答题
|
较难
(0.4)
名校
【推荐1】在平面直角坐标系中,直线
分别交
轴,
轴于点
,点
;点
在
轴负半轴上,且
,点
在直线
上,点
是
轴上的一个动点,设点
的横坐标为
.
(1)求直线
的函数表达式;
(2)连接
,
,若点
在
轴负半轴上,且
的面积等于
面积的一半,求出
的值;
(3)请直接写出
的最小值;
(4)以
为斜边作等腰直角三角形
,使点
落在线段
或线段
上,请直接写出所有符合条件的
的值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/736adffb9e9e4e11bd071c0bc7b50092.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.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/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a23f35ebcd9799d82c1e41c09781a4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c61622eb7fa6fabe6bd361bd5aa6107.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/11/413341c3-c67c-4ec3-8d27-39ef50561309.png?resizew=161)
(1)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/167d31eb8432b5c0364316e5048c23dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12225a1a1eda07908309f8100cc34726.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(3)请直接写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdf479faa4cf148239ae5bc62bd3c20e.png)
(4)以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/881129039cb98be128af55ffa1d3b7dc.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】阅读下列材料,完成相应任务.
数学活动课上,老师提出了如下问题:
如图1,已知
中,
是
边上的中线.求证:
.
智慧小组的证法如下:
证明:如图2,延长
至
,使
,
∵
是
边上的中线∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/532aece6cfd67e2a97977eed978dbf2b.png)
在
和
中![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41d8acf42b7357262506044e16d676eb.png)
∴
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39ef7ae57a07a8f820950069b7f5bfab.png)
在
中,
(依据一)
∴
.
任务一:上述证明过程中的“依据一”是指:____________________;
归纳总结:上述方法是通过延长中线
,使
,构造了一对全等三角形,将
,
,
转化到一个三角形中,进而解决问题,这种方法叫做“倍长中线法”.“倍长中线法”多用于构造全等三角形和证明边之间的关系.
任务二:如图3,
,
,则
的取值范围是_____________;
任务三:如图4,在图3的基础上,分别以
和
为边作等腰直角三角形,即在
中,
,
;
中,
,
.连接
.试探究
与
的数量关系,并说明理由.
数学活动课上,老师提出了如下问题:
如图1,已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/11d168264acad9c8eab2ec4176916dc3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/27/b6383832-621d-408f-9502-61c684b3f6c3.png?resizew=143)
智慧小组的证法如下:
证明:如图2,延长
![](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/0ad98ad714864041a632ca949308e417.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/532aece6cfd67e2a97977eed978dbf2b.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f2281cb6df0c3c518ce5ed19a02b57e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf94bbdc11e2942b20368833c7d7a787.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41d8acf42b7357262506044e16d676eb.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3d62d8fa4b680a59ece602d06167ee3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39ef7ae57a07a8f820950069b7f5bfab.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/002194e7f13d4e51efd265f86007642d.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d168264acad9c8eab2ec4176916dc3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/27/7f1f3494-4145-49b6-aec1-60a003263b79.png?resizew=143)
任务一:上述证明过程中的“依据一”是指:____________________;
归纳总结:上述方法是通过延长中线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ad98ad714864041a632ca949308e417.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/03902478df1a55bc99703210bccab910.png)
任务二:如图3,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/27/84c15b0b-1850-4364-85cc-bda92b355fe9.png?resizew=135)
任务三:如图4,在图3的基础上,分别以
![](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/f1a3b94566843e92ce775ff6bdf386fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01e94dacf9ef98c98de9344a77079cf5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48a277db452e76240ec83ec6a2864bdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02763d661acaa5b3799585f9fa64977e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8895a79135b7d28d23f9fbe5447656c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49cb6392b1f859954303066037c5f5fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/27/892193fe-f36c-489e-9590-9095d78ae1cc.png?resizew=135)
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解题方法
【推荐3】【操作发现】
![](https://img.xkw.com/dksih/QBM/2021/6/29/2753660790931456/2759152591110144/STEM/ee7bf2f1-0d93-4c94-8e1f-42c505cfc101.png)
![](https://img.xkw.com/dksih/QBM/2021/6/29/2753660790931456/2759152591110144/STEM/5b04763b-1988-4883-899b-21ea37d95edb.png)
(1)如图1,在边长为1个单位长度的小正方形组成的网格中,
的三个顶点均在格点上.
①请按要求画图:将
绕点
按顺时针方向旋转90°,点
的对应点为
,点
的对应点为
;
②连接
,此时
______°;
【问题解决】
在某次数学兴趣小组活动中,小明同学遇到了如下问题:
(2)如图2,在等边
中,点
在内部,且
,
,
,求
的长.
经过同学们的观察、分析、思考、交流,对上述问题形成了如下想法:将
绕点
按顺时针方向旋转60°,得到
,连接
,寻找
、
、
三边之间的数量关系.…请参考他们的想法,完成该问题的解答过程;
【学以致用】
(3)如图3,在等腰直角
中,
,
为
内一点,且
,
,
,求
;
【思维拓展】
(4)注意:从以下①②中,你任意选择一道题解答即可.
①等腰直角
中,
,
为
内部一点,若
,则
的最小值=______
②如图4,若点
是正方形
外一点,
,
,
,求
的度数.
![](https://img.xkw.com/dksih/QBM/2021/6/29/2753660790931456/2759152591110144/STEM/ee7bf2f1-0d93-4c94-8e1f-42c505cfc101.png)
![](https://img.xkw.com/dksih/QBM/2021/6/29/2753660790931456/2759152591110144/STEM/5b04763b-1988-4883-899b-21ea37d95edb.png)
(1)如图1,在边长为1个单位长度的小正方形组成的网格中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
①请按要求画图:将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.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/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c578d3a17de6f47abaaeca5ab778e7f.png)
②连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6655cc150ddc9deba2254780984d0024.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80e435d643780ed87871dcc27fadda45.png)
【问题解决】
在某次数学兴趣小组活动中,小明同学遇到了如下问题:
(2)如图2,在等边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/491c3a4f72b84ebadd28b90711435adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eea78bf026d76f1cb9cc3dc9349a193.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d61fb3b92bd08707aca2f3e31ae16a68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
经过同学们的观察、分析、思考、交流,对上述问题形成了如下想法:将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9524e3810e06dc781285f1289e75d653.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f8c0c8a16d9e56d7db6a9d8657faf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a99e1ad0d6fb0f13be56d09086366c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
【学以致用】
(3)如图3,在等腰直角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3015db5ca1f49bb7bad43657e06863ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ced8225ff27c8e3e1897b8629312d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942a9a6bde4a5b9803b68b1e9065de62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
【思维拓展】
(4)注意:从以下①②中,你任意选择一道题解答即可.
①等腰直角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/643bd6c1545b531e70f05913dc28bda0.png)
②如图4,若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/491c3a4f72b84ebadd28b90711435adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08aa6fd52f3933cbded9ce8c880b4a10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a04260d53a143dac4b4f7a8528e1a7dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb686e4f5e3938575bc547e849d5513f.png)
您最近一年使用:0次
解答题-证明题
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较难
(0.4)
名校
【推荐1】如图1,在四边形ABCD中,
,
,
.
![](https://img.xkw.com/dksih/QBM/2022/7/7/3017543308902400/3051229173760000/STEM/9ca63edaec5540f598fe5d54542dc852.png?resizew=554)
(1)求∠ACD的度数;
(2)如图2,F为线段CD的中点,连接BF,求证:
;
(3)如图3,若
,线段BC上有一动点M,连接OM,将
沿OM所在直线翻折至
的位置,P为B的对应点,连接PA,PC,当
的值最小时,设O到直线PC的距离为
,PC的长度为
,直接写出
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/622d184859249054afbe9cc7aea5e8eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://img.xkw.com/dksih/QBM/2022/7/7/3017543308902400/3051229173760000/STEM/9ca63edaec5540f598fe5d54542dc852.png?resizew=554)
(1)求∠ACD的度数;
(2)如图2,F为线段CD的中点,连接BF,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd8f0a7ce3aff4332a2937e6ebde7af.png)
(3)如图3,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d0f993cf5b6ef5f2585b21c557ac331.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60f8a33ab7b6d46fc6aa88c370e54983.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a51268fce97426487c3338d6ec3d571.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d26381caa8fdcb797d4fd10cf8d9427.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80b53eab97158937f92039c1e133b0f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f285174fbf90a9742de57c1e53224cff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0bc9e7badfafa2bfd9ece72da1ac71a.png)
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【推荐2】如图,点E是正方形ABCD对角线上一点,连接DE、BE,过E点作EF⊥DE与直线BC交于点F,连接DF.
(1)如图1,当F在边BC上时.
①求证:DE=BE;
②判断△DEF的形状,说明理由;
(2)如图2,当F在BC延长线上时,求证:AB﹣CF=
CE.
(1)如图1,当F在边BC上时.
①求证:DE=BE;
②判断△DEF的形状,说明理由;
(2)如图2,当F在BC延长线上时,求证:AB﹣CF=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://img.xkw.com/dksih/QBM/2021/7/12/2762434476498944/2822888626298880/STEM/673e1673-68c9-4c70-8e7c-b580929816ac.png)
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【推荐3】背景材料:
在学习全等三角形知识时,数学兴趣小组发现这样一个模型,它是由两个共顶点且顶角相等的等腰三角形构成.在相对位置变化的同时,始终存在一对全等三角形.通过资料查询,他们知道这种模型称为手拉手模型.
例如:如图1,两个等腰直角三角形△ABC和△ADE,∠BAC=∠EAD=90°,AB=AC,AE=AD,如果把小等腰三角形的腰长看作是小手,大等腰三角形的腰长看作大手,两个等腰三角形有公共顶点,类似大手拉着小手,这个就是手拉手模型,在这个模型中易得到△ABD≌△ACE.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/10/d92c7de3-5731-4fd4-a6e0-88974393c00a.png?resizew=514)
学习小组继续探究:
(1)如图2,已知△ABC,以AB,AC为边分别向△ABC外作等边△ABD和等边△ACE,请作出一个手拉手图形(尺规作图,不写作法,保留作图痕迹),并连接BE,CD,证明BE=CD;
(2)小刚同学发现,不等腰的三角形也可得到手拉手模型,例如,在△ABC中AB>AC,DE∥BC,将三角形ADE旋转一定的角度(如图3),连接CE和BD,证明△ABD∽△ACE.
学以致用:
(3)如图4,四边形ABCD中,∠CAB=90°,∠ADC=∠ACB=α,tanα=
,CD=5,AD=12.请在图中构造小刚发现的手拉手模型求BD的长.
在学习全等三角形知识时,数学兴趣小组发现这样一个模型,它是由两个共顶点且顶角相等的等腰三角形构成.在相对位置变化的同时,始终存在一对全等三角形.通过资料查询,他们知道这种模型称为手拉手模型.
例如:如图1,两个等腰直角三角形△ABC和△ADE,∠BAC=∠EAD=90°,AB=AC,AE=AD,如果把小等腰三角形的腰长看作是小手,大等腰三角形的腰长看作大手,两个等腰三角形有公共顶点,类似大手拉着小手,这个就是手拉手模型,在这个模型中易得到△ABD≌△ACE.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/10/d92c7de3-5731-4fd4-a6e0-88974393c00a.png?resizew=514)
学习小组继续探究:
(1)如图2,已知△ABC,以AB,AC为边分别向△ABC外作等边△ABD和等边△ACE,请作出一个手拉手图形(尺规作图,不写作法,保留作图痕迹),并连接BE,CD,证明BE=CD;
(2)小刚同学发现,不等腰的三角形也可得到手拉手模型,例如,在△ABC中AB>AC,DE∥BC,将三角形ADE旋转一定的角度(如图3),连接CE和BD,证明△ABD∽△ACE.
学以致用:
(3)如图4,四边形ABCD中,∠CAB=90°,∠ADC=∠ACB=α,tanα=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b2a698891d42c70b597f0da4f215f09.png)
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【推荐1】如图(1),Rt△AOB中,∠A=90°,
,OB=2
,∠AOB的平分线OC交AB于C,过
作与
垂直的直线
.动点
从点
出发沿折线
以每秒1个单位长度的速度向终点
运动,运动时间为t秒,同时动点Q从点C出发沿折线
以相同的速度运动,当
点到达
点时,
同时停止运动.
(1)OC= ,BC= ;
(2)设△CPQ的面积为S,求S与t的函数关系式;
(3)当P在OC上Q在ON上运动时,如图(2),设PQ与OA交于点M,当
为何值时,△OPM为等腰三角形?求出所有满足条件的t值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc1eb76fe74cba30f7cbcde349ba80da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e9f7d1272b7344346b58b660aa260a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/755091f2ac4e61c30fbc2a7ff3647d37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e0aaeabbf48c53f325dd1182b7b48f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6bce3d91ca23b86d8c6625f2632e437.png)
(1)OC= ,BC= ;
(2)设△CPQ的面积为S,求S与t的函数关系式;
(3)当P在OC上Q在ON上运动时,如图(2),设PQ与OA交于点M,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
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【推荐2】在矩形
中,
,
.分别以
,
边所在的直线为x轴,y轴建立如图所示的平面直角坐标系.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/15/b405a96f-8772-4d2d-929b-7b7e4f4fb397.jpg?resizew=463)
(1)如图1,将
沿对角线
翻折,交
于点P,求点P的坐标;
(2)如图2,已知H是
上一点,且
,
于点
,求四边形
的面积;
(3)如图3,点
,点
是
上一点,且
,
是直线
上的一个动点,在x轴上方的平面内是否存在另一个点N,使以O、D、M、N为顶点的四边形是菱形?若存在,直接写出点N的坐标;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/bb2d3f02cb9007cd4a90ea30f6dd8181.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/15/b405a96f-8772-4d2d-929b-7b7e4f4fb397.jpg?resizew=463)
(1)如图1,将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/173bc7a36757d77f01213411edd25241.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(2)如图2,已知H是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e91769bc2f435e542e1ef018ddba7f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324161ba35929074fc09f5444630fd3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68d0e1cf4924b1c342d75de0aff3e21f.png)
(3)如图3,点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98b1854b87a9153f01036c580d9f29d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13ef9cf01e628b84d62de0c3f9bff617.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
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【推荐1】如图①,在正方形ABCD中,点N、M分别在边BC、CD上,连接AM、AN、MN.∠MAN=
,将△AMD绕点A顺时针旋转
,点D与点B重合,得到△ABE. 易证:
,从而得
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/14/e696e3ce-9e1e-42a5-96d7-6cee38585c10.png?resizew=256)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/14/080118a8-923a-40e7-843d-ffbf5b110036.png?resizew=226)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/14/e3b83fdb-692f-458d-98cf-3388fdfa9d06.png?resizew=212)
【实践探究】
(1)如图②,在正方形ABCD中,点E,F在对角线BD上,且
,请你直接写出线段BE,EF,FD之间的数量关系___.
【拓展】
(2)如图③,正方形ABCD的边长为10,点P为边CD上一点,
于E,Q为BP中点,连接CQ并延长交BD于点F,且
,则PD的长为___.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2ff7caec4fdd8fb54a3ffbff9692414.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02f45ae25b1071c617d92b8e40bc75c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41a760864f397a1df8738e9d8af463c7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/14/e696e3ce-9e1e-42a5-96d7-6cee38585c10.png?resizew=256)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/14/080118a8-923a-40e7-843d-ffbf5b110036.png?resizew=226)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/14/e3b83fdb-692f-458d-98cf-3388fdfa9d06.png?resizew=212)
【实践探究】
(1)如图②,在正方形ABCD中,点E,F在对角线BD上,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1660e78fa0ebf52a5d9045516422b6c.png)
【拓展】
(2)如图③,正方形ABCD的边长为10,点P为边CD上一点,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d31767eb718a0327eca546fe6a189cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bebd189aed25543fe2a3094ddf9973f.png)
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【推荐2】如图,在正方形ABCD中,P是边BC上的一个动点(不与点B,C重合),作点B关于直线AP的对称点E,连接AE,再连接DE并延长交射线AP于点F,连接BF和CF.
![](https://img.xkw.com/dksih/QBM/2022/3/31/2948200168734720/2949512771452928/STEM/3f6f64c381b64d96b0ec3cbf6a8ac9a2.png?resizew=180)
(1)若∠BAP=
,则∠AED= (用含
的式子直接填空);
(2)求证:点F在正方形ABCD的外接圆上;
(3)求证:AF﹣CF=
BF.
![](https://img.xkw.com/dksih/QBM/2022/3/31/2948200168734720/2949512771452928/STEM/3f6f64c381b64d96b0ec3cbf6a8ac9a2.png?resizew=180)
(1)若∠BAP=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
(2)求证:点F在正方形ABCD的外接圆上;
(3)求证:AF﹣CF=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
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