1 . 数学课上,王老师布置如下任务:如图,已知
,点
是射线
上的一个定点,在射线
上求作点
在
和
之间),使
.
下面是小路设计的尺规作图过程.
作法:作线段
的垂直平分线l,直线l交射线
于点C,则点C即为所求.
根据小路设计的尺规作图过程,
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/27/a9948107-753a-4ffc-abea-60d2401c1613.png?resizew=202)
(1)使用直尺和圆规,补全图形;(保留作图痕迹)
(2)完成下面的证明:
证明:连接
,
∵直线l为线段
的垂直平分线,
∴
,( )(填推理的依据)
∴
,
∴
( )(填推理的依据)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45c354f194d9410d119c5054548de93.png)
(3)能否在射线
上再求作点
,使
.若能简要说明作法,并使用直尺和圆规画出图形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39da1b9bc3e46a4f9317c393978bfb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f2801d22074121bca2fcf0cd2531ef2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45c354f194d9410d119c5054548de93.png)
下面是小路设计的尺规作图过程.
作法:作线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
根据小路设计的尺规作图过程,
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/27/a9948107-753a-4ffc-abea-60d2401c1613.png?resizew=202)
(1)使用直尺和圆规,补全图形;(保留作图痕迹)
(2)完成下面的证明:
证明:连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
∵直线l为线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ac2e854df9867fea0ace9156bc215da.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14b1848fa4f378761a9d734e9d0aa9de.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a77cc08ff91bb2f732109d8a42ee365.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45c354f194d9410d119c5054548de93.png)
(3)能否在射线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d6c3cb56e4fcc971761655bc401ec7b.png)
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2 . 数学活动课上,小明同学根据学习函数的经验,对函数的图象、性质进行了探究.如图1,已知在
中,
,
,
,点P为AB边上的一个动点,连接PC,设
,
,
![](https://img.xkw.com/dksih/QBM/2022/1/16/2895927304634368/2934571169914880/STEM/184fab3d-5b3c-4012-90b8-5cb1a686684a.png?resizew=317)
(1)当
时,则 x= ;y= ;
(2)填表:
(说明:补全表格时相关数值保留一位小数)(参考数据:
;
).
(3)试求y与x之间的函数关系式;
a、建立平面直角坐标系,如图2,描出剩余的点,并用光滑的曲线画出该函数的图象;
b、结合画出的函数图象,写出该函数的两条性质:
① ;
② .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f8f88798ec42a58dccd212586382b23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a355958abf7dc0f2eb949584cb87907b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44f4bcb7ddcdbb66f0304d0531e84c6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40eee6f84b2af5e06da1cd3d0a1f3a0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa03b06bc3ffc95899645c08b21fcd1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2a80b46e3ef7314b35df0517c969608.png)
![](https://img.xkw.com/dksih/QBM/2022/1/16/2895927304634368/2934571169914880/STEM/184fab3d-5b3c-4012-90b8-5cb1a686684a.png?resizew=317)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df2e118d8156830746055c1b2e759ab0.png)
(2)填表:
x/cm | 0 | 0.5 | 1 | 1.5 | 2 | 2.5 | 3 | 3.5 | 4 |
y/cm | 2 | 1.8 | 1.7 | 2 | 2.3 | 2.6 | 3 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47bb3f35e3db7c1f3a3dd3eb20151b5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4f0684b92d6d24d90a6fb39d3d6529d.png)
(3)试求y与x之间的函数关系式;
a、建立平面直角坐标系,如图2,描出剩余的点,并用光滑的曲线画出该函数的图象;
b、结合画出的函数图象,写出该函数的两条性质:
① ;
② .
您最近一年使用:0次
2022-03-12更新
|
213次组卷
|
2卷引用:江西省宜春市宜丰中学2022-2023学年八年级下学期期中数学试题
名校
3 . 如图,在
中,
的角平分线
交
于点D,并在射线
上另取一点E(不与A重合),使得
,连接
;(保留作图痕迹,不写作法)
(2)在(1)所作图形中,若D恰为线段
的中点,求证;
.(请补全下面的证明过程,不写证明理由)
证明:∵D为
中点
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/532aece6cfd67e2a97977eed978dbf2b.png)
∴在
和
中
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6ad3e834b13b8cd382b406612d5f4a2.png)
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/038df92742be9dca6e3d62a262c6893e.png)
∴
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/102ebb908833439c37e364f60f1d4ebb.png)
又∵
是
的角平分线
∴②
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e52154425097228893a63b790e1c20d9.png)
∴③
又∵![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5b59f0e6f7fa9c50e7f5cc146ba1af1.png)
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
由此发现一个结论,请完成下列命题:
如果一个三角形的一个内角的角平分线又是对边上的中线,那么④ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/518586d91b63569fc317b323835a0c2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(2)在(1)所作图形中,若D恰为线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
证明:∵D为
![](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/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b265d121f9ebc13671a5719604476a.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6ad3e834b13b8cd382b406612d5f4a2.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/038df92742be9dca6e3d62a262c6893e.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17101383eb0787edaaa35adfcd20d5c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/102ebb908833439c37e364f60f1d4ebb.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
∴②
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e52154425097228893a63b790e1c20d9.png)
∴③
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5b59f0e6f7fa9c50e7f5cc146ba1af1.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
由此发现一个结论,请完成下列命题:
如果一个三角形的一个内角的角平分线又是对边上的中线,那么④ .
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4 . 数学课上,老师带领同学们以直角三角形的两条直角边为邻边,尺规作图作一个矩形.如图1,在
中,
,尺规作图:求作矩形
.小辉同学经过思考后,回答他的做法如下:作
边的垂直平分线
,
交
于点 O,作射线
,在线段
的延长线上截取
,连接
,则四边形
为矩形.
(2)完成下面的证明,并在括号内填写相应的依据;
证明:由作法可知,
,
,
∴ 四边形
是平行四边形( )
,
∴ 四边形
是矩形( )
(3)请你用不同于小辉的方法,在图2中尺规作图,作出矩形
(保留作图痕迹,不写作法).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf1438142deeac876fc7dc50552e552.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf1438142deeac876fc7dc50552e552.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c940869dd66321d1132828a95cb5353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7e545f31f7cc57a31843f5adfd02941.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)完成下面的证明,并在括号内填写相应的依据;
证明:由作法可知,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fd64a51dc0617e5e1e5dd61f80bbe35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b9ea68dbddf33f0fed8f35a1fd5c90b.png)
∴ 四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d6808b55943e0ab815da922bf1b095e.png)
∴ 四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(3)请你用不同于小辉的方法,在图2中尺规作图,作出矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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5 . 如图,矩形
的对角线
交于点O,
于M.
的垂线,垂足为N,连接
、
(保留作图痕迹,不写作法,不写结论).
(2)补全推理过程:
在矩形
中
∵
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d2530e7023b2345c651e8f53629ff1.png)
∴
∵
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d910571a3e7b0ee39fc2e99cc6a80f70.png)
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0deed51a0bf56bee6cb785f29802ffa4.png)
即 ,
∴ ;
在
和
中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a6628d0bfe1bc50c8fc97233e849c03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e987f381f76893789bc051392c56b083.png)
∴
∴四边形
为平行四边形( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d578394cd8e4d7a705599269c512960.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52ab924e3692515bd8be4c36472a959a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
(2)补全推理过程:
在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dceb5cc71fc50f20649f6b9535fd914.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d2530e7023b2345c651e8f53629ff1.png)
∴
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52ab924e3692515bd8be4c36472a959a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d910571a3e7b0ee39fc2e99cc6a80f70.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0deed51a0bf56bee6cb785f29802ffa4.png)
即 ,
∴ ;
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7f9fba8a4098c1a0515286eb8d616dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e817a54942ebf021a2967ff0c51a8111.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a6628d0bfe1bc50c8fc97233e849c03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e987f381f76893789bc051392c56b083.png)
∴
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b977f9880c3acc912c36aa3e2df56c9.png)
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6 . 下面是小明设计的作菱形
的尺规作图过程.
已知:四边形
是平行四边形.
求作:菱形
(点
在
上,点
在
上).
作法:如图,
①以
为圆心,
长为半径作弧,交
于点
;
②以
为圆心,
长为半径作弧,交
于点
;
③连接
,所以四边形
为所求的菱形.
(2)完成下面的证明.
证明:∵
,
,
∴______
______,
在平行四边形
中,
,即
,
∴四边形
为______形,
∵
,
∴四边形
为菱形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
已知:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
求作:菱形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
作法:如图,
①以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
②以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.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/2a30f3a8b673cc28bd90c50cf1a35281.png)
③连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
(2)完成下面的证明.
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14833dbeed409b33acd4c9071fd0be36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4e92f48e9bfe12d145f7d2a2f0360d0.png)
∴______
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6706fe00b4e231e62d9ecbec567d526b.png)
在平行四边形
![](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/9d61d846cbc5220533271c962b85c4b5.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14833dbeed409b33acd4c9071fd0be36.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
您最近一年使用:0次
7 . 已知:平行四边形
,
求作:菱形
,使点E、F分别在
边上.
下面是小明设计的尺规作图过程
作法:如图,
;
②分别以A、C为圆心,大于
长为半径作弧,两弧交于M、N两点;
③连接
,分别与
交于E、F、O三点;
④连接
.
四边形
即为所求.
根据小明设计的尺规作图过程,
(1)使用直尺和圆规,补全图形:(保留作图痕迹)
(2)完成下面的证明.
证明:∵
__________,
___________.
∴
是
的垂直平分线,
∴
,
,
∵四边形
是平行四边形,
∴
.
∴
.
在
和
中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/104a3b35a28ce1c6d35204c981dbf21c.png)
∴
.
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcf2e3236ea30ee2c37928b98041f13a.png)
又∵![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a23f35ebcd9799d82c1e41c09781a4c.png)
∴四边形
是平行四边形,(对角线互相平分的四边形是平行四边形)
∵
,
∴四边形
是菱形.(______________)(填推理的依据)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
求作:菱形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6c8b21a087818284c9cd909cc56c814.png)
下面是小明设计的尺规作图过程
作法:如图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
②分别以A、C为圆心,大于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c93148adbc6e856da9a9d263f485d003.png)
③连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/468a30c8f273eed3f702ce4235ad0898.png)
④连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/851ab1aa713a2d1c21e886c8acd3f0d2.png)
四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
根据小明设计的尺规作图过程,
(1)使用直尺和圆规,补全图形:(保留作图痕迹)
(2)完成下面的证明.
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1039601edd7326b628a3201a3d4af948.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28f69b26816ac72e2e2e7d9ea0578598.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8de4a54cc7818be87a239f6de5f5d05b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a23f35ebcd9799d82c1e41c09781a4c.png)
∵四边形
![](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/6727907a385b2e5d6b4b4f9295bb6550.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ad8a237af55a35a37f81a54332ddc17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f8fa902d4f366d8b777fa3db6a0df84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/104a3b35a28ce1c6d35204c981dbf21c.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcc8bebee89c634baea630ba1ffa3871.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcf2e3236ea30ee2c37928b98041f13a.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a23f35ebcd9799d82c1e41c09781a4c.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8de4a54cc7818be87a239f6de5f5d05b.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
您最近一年使用:0次
名校
8 . 下面是小东设计的“过圆外一点作圆的切线”的尺规作图过程.
已知:如图,
及
外一点P.求作:过点P的
的切线.
作法:
①连接
,分别以点O、点P为圆心,大于
的长为半径作弧,两弧交于点M、点N,作直线
交
于点T:
②以点T为圆心,
的长为半径作圆,交
于点A、点B;
③作直线
,
.
所以直线
,
就是所求作的
的切线.
根据小东设计的尺规作图过程,
(1)使用直尺和圆规,补全图形(保留作图痕迹):
(2)完成下面的证明.
证明:连接
.
是
的直径,
°( )(填推理的依据).
.
又
OA为
的半径,
直线
是
的切线( )(填推理的依据).
同理可证,直线
也是
的切线.
已知:如图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/3/2e5a4806-18b0-4232-aea6-b80d0934de6d.png?resizew=140)
作法:
①连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b64dc1ab9bf65cfdaac7633e9a7958ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
②以点T为圆心,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ea2cde209f39851e2674877d30e3e84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
③作直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
所以直线
![](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/3d97cdc586744d208b6f69c9813af977.png)
根据小东设计的尺规作图过程,
(1)使用直尺和圆规,补全图形(保留作图痕迹):
(2)完成下面的证明.
证明:连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cd84460903114fae02d1c9e351aa12f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9347ab0d001ed7e8f51f9886ce88ac64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/919d2289a9a69296e664bbb744127aaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aab6072649dfb502fc43b68bfcbfdc6c.png)
又
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16f3d198e76391779fa3badc848c8ac8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16f3d198e76391779fa3badc848c8ac8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
同理可证,直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
您最近一年使用:0次
2023-12-16更新
|
287次组卷
|
2卷引用:北京师范大学附属中学2023-2024学年九年级上学期期中数学试题
9 . 在矩形
中,
和
相交于O点,
.
上求作点E,使
;(不写作法,保留作图痕迹)
(2)在(1)的条件下,连接
并延长交
于点F,连接
并延长交
于点G,连接
,请在图中补全图形并证明四边形
是菱形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc1eb76fe74cba30f7cbcde349ba80da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf1438142deeac876fc7dc50552e552.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bd164ec56854ff7a990057a06e8fc14.png)
(2)在(1)的条件下,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecff6005f926665a926c07ad62e0f032.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d2783577c5f0c2e38d26650acb3c49b.png)
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名校
10 . 如图,在平行四边形
中,已知
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/10/c80458cc-d98e-4435-84e7-e212799de64a.png?resizew=174)
(1)实践与操作:作
的平分线交
于点
,在
上截取
,连接
.(要求:尺规作图,保留作图痕迹,不写作法)
(2)求证:四边形
是菱形.(在下列横线上补全推理过程或推理依据)
证明:四边形
是平行四边形,
∴
,
∴ ① ,( ② )
∵
平分
,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb88f0386fc3ae7d108e79305e2e712f.png)
∴ ③
④
由(1)得:
,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/027f82d255ca6058000c9683a6cffd7b.png)
又∵ ⑤
∴四边形
是平行四边形,( ⑥ )
∵ ⑦
∴四边形
是菱形.( ⑧ )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deb6694f3443cc5f4d09948679251b61.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/10/c80458cc-d98e-4435-84e7-e212799de64a.png?resizew=174)
(1)实践与操作:作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14833dbeed409b33acd4c9071fd0be36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
(2)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
证明:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
∴ ① ,( ② )
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb88f0386fc3ae7d108e79305e2e712f.png)
∴ ③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d3006396a74ac1f3da6243cdf180e51.png)
由(1)得:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14833dbeed409b33acd4c9071fd0be36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/027f82d255ca6058000c9683a6cffd7b.png)
又∵ ⑤
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
∵ ⑦
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
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