如图,在
ABCD中,点E,F分别是边AB,CD的中点,
(1)求证:△CFB≌△AED;
(2)若∠ADB=90°,判断四边形BFDE的形状,并说明理由;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81a5328919a7cec382c2e91c9c528fc1.png)
(1)求证:△CFB≌△AED;
(2)若∠ADB=90°,判断四边形BFDE的形状,并说明理由;
![](https://img.xkw.com/dksih/QBM/2018/5/7/1940265419997184/1941845502083072/STEM/49b1d3025d3a4c51acbf2c218a14daf8.png?resizew=130)
17-18八年级下·福建厦门·期中 查看更多[6]
【全国校级联考】福建省厦门市六校2017-2018学年下学期八年级期中联考数学试卷山东省德州市六校2017-2018学年八年级下学期第二次月考数学试题广东省汕头市龙湖实验中学2018-2019学年八年级下学期期中考试数学试题四川省内江市第二中学2018-2019学年八年级下学期期中数学试题(已下线)期末测试卷【A卷】-2021-2022学年八年级数学上册同步必刷基础拓展单元卷(人教版)安徽省芜湖市第二十九中学2021-2022学年八年级下学期期中考试数学试题
更新时间:2018-05-09 22:37:41
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相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】
中,
,
,D为
外一点.
(1)【探究发现】如图1,点D在边
下方,
.学校的数学兴趣小组的同学们尝试探究此时线段
、
、
之间的数量关系.他们的思路是这样的,作
,取
,连接
.易证
.通过等量代换得到线段之间的数量关系.请根据同学们的思路,写出
的证明过程.
(2)【迁移运用】如图2,点D在边
上方,
.猜想线段
、
、
之间的数量关系,并证明你的结论.
(3)【延伸拓展】如图3,在四边形
中,
,若
,
,请直接写出
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c287bb15494297df234f700f9f3a90d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b83e7c8586eef5596aef5fb5160a196a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
(1)【探究发现】如图1,点D在边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86857e2e1e3f1a01dbfc32219dcef685.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3182db896bc2462331796e2a6108363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e63cb48f94026b18ed79d3386aa797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c3b6748f4ce6f3f588c2ab204f231bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0213c5787a5a6b38d11bceca5567f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5eea6c93b2de6a6d0af908f5a3eca97e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5eea6c93b2de6a6d0af908f5a3eca97e.png)
(2)【迁移运用】如图2,点D在边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86857e2e1e3f1a01dbfc32219dcef685.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3182db896bc2462331796e2a6108363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
(3)【延伸拓展】如图3,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de08ac9282347f76be555415bf206c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccf3746205daae4787d8e31d74ba79e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee82a25c3ccc4bd94f3f528ff3e95713.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3182db896bc2462331796e2a6108363.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/27/a4cc2d56-0382-40ab-811a-279931520928.png?resizew=383)
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解答题-问答题
|
适中
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【推荐2】如图,
中,
,E、F为线段BC上两点,连接FA并延长到点D,连接DE,使
,且
.
![](https://img.xkw.com/dksih/QBM/2022/1/13/2893583161098240/2894852557832192/STEM/9a0dcbb7-c738-4df0-8011-a34b311bd290.png?resizew=226)
(1)找到与
相等的角,并说明理由;
(2)若
,
,求CE的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6ab4d90c75a3eba6e2dfbdd91d2d8a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a510a3eb906b3ef0760b0d1723d11ae.png)
![](https://img.xkw.com/dksih/QBM/2022/1/13/2893583161098240/2894852557832192/STEM/9a0dcbb7-c738-4df0-8011-a34b311bd290.png?resizew=226)
(1)找到与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c543c3ddc3723fde6bbfca3ea3b921b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cc4908fa31c032d29c1b1057d7dbaa0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4aca5534bce25acaeb7379deed8f8f.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
名校
【推荐1】如图1,在
中,
;
是
的中点,
是
的中点,作
于点
,延长
至点
,使
,连接
、
、
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/2/93158464-17de-4009-8c65-af8684ca5a2d.png?resizew=309)
(1)如图1,求证:四边形
是平行四边形;
(2)如图2,连接
交
于点
,若
,请直接写出图2中所有长度等于
的线段.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.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/58cc90fee532e50d319081d571410421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acb510bed6b8299e7de61a9a5767b82f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/2/93158464-17de-4009-8c65-af8684ca5a2d.png?resizew=309)
(1)如图1,求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23125a1865f3e6203a207d04c93129c5.png)
(2)如图2,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e55e398e8520d8a36fb5a625a085b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb023313112cd8a6068d013fdcc9a193.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b0a6fbc5dd2364426bc27f14add932c.png)
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解答题-证明题
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适中
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【推荐2】阅读理解题: 如图,在△ABC中,AD是BC边上的中线,且AD=
BC.
求证:∠BAC=90°.
![](https://img.xkw.com/dksih/QBM/2014/12/12/1573767903510528/1573767909670912/STEM/8b6e8d2170c4461f9b8f102c871a1236.png)
证明:∵AD=
BC,BD=CD=
BC,
∴AD=BD=DC,
![](https://img.xkw.com/dksih/QBM/2014/12/12/1573767903510528/1573767909670912/STEM/a771606ab14d4271b045a09db461dbb4.png)
∴ADB和 ADC都是等腰三角形
∴∠B=∠BAD,∠C=∠CAD,
∵∠B+∠BAD+∠CAD+∠C=180°,
∴∠BAD+∠CAD=90°,即∠BAC=90°.
(1)此题实际上是直角三角形的另一个判定方法,请你用文字语言叙述出来.
(2)直接运用这个结论解答题目:一个三角形一边长为2,这边上的中线长为1,另两边之和为1+
,求这个三角形的面积.
【知识储备:勾股定理:在直角三角形中.两直角边的平方和等于斜边的平方.】
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
求证:∠BAC=90°.
![](https://img.xkw.com/dksih/QBM/2014/12/12/1573767903510528/1573767909670912/STEM/8b6e8d2170c4461f9b8f102c871a1236.png)
证明:∵AD=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
∴AD=BD=DC,
![](https://img.xkw.com/dksih/QBM/2014/12/12/1573767903510528/1573767909670912/STEM/a771606ab14d4271b045a09db461dbb4.png)
![](https://img.xkw.com/dksih/QBM/2014/12/12/1573767903510528/1573767909670912/STEM/59db4797024d4a77bce54c07340ca12b.png)
∴∠B=∠BAD,∠C=∠CAD,
∵∠B+∠BAD+∠CAD+∠C=180°,
∴∠BAD+∠CAD=90°,即∠BAC=90°.
(1)此题实际上是直角三角形的另一个判定方法,请你用文字语言叙述出来.
(2)直接运用这个结论解答题目:一个三角形一边长为2,这边上的中线长为1,另两边之和为1+
![](https://img.xkw.com/dksih/QBM/2014/12/12/1573767903510528/1573767909670912/STEM/ea8ed15d99e8444fbae35e3f21066388.png)
【知识储备:勾股定理:在直角三角形中.两直角边的平方和等于斜边的平方.】
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解答题-证明题
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适中
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【推荐1】如图,在矩形ABCD中,点E是边CD上任意一点(点E与点C、D不重合),过点A作AF⊥AE,交边CB的延长线于点F,联结EF交边AB于点G,联结AC.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/6/16/6bf8d203-d53e-4fb8-953d-a9afaf66fe1a.png?resizew=129)
(1)求证:△AEF∽△DAC;
(2)如果FE平分∠AFB,联结CG,求证:四边形AGCE为菱形.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/6/16/6bf8d203-d53e-4fb8-953d-a9afaf66fe1a.png?resizew=129)
(1)求证:△AEF∽△DAC;
(2)如果FE平分∠AFB,联结CG,求证:四边形AGCE为菱形.
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解答题-证明题
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适中
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【推荐2】如图所示,已知AB=AC,CB平分∠ACD,CD=CA,E是BC上一点,连接DE并延长交AB于F.
![](https://img.xkw.com/dksih/QBM/2022/4/9/2954304314793984/2965914469933056/STEM/5e7e7384-8d4c-4fc3-871d-8f3882ee6dde.png?resizew=229)
(1)求证:
AEC≌
DEC;
(2)连接BD,求证四边形ABDC是菱形;
(3)若F是AB的中点,EF=3,求AE的长.
![](https://img.xkw.com/dksih/QBM/2022/4/9/2954304314793984/2965914469933056/STEM/5e7e7384-8d4c-4fc3-871d-8f3882ee6dde.png?resizew=229)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4cba95fc7d4853a243f8e3fb20ce70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4cba95fc7d4853a243f8e3fb20ce70.png)
(2)连接BD,求证四边形ABDC是菱形;
(3)若F是AB的中点,EF=3,求AE的长.
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