1 . 作图:
如图,
,按以下步骤使用尺规作图(保留作图痕迹,不写作法):
①作
的平分线
;
②在
上任意画出点E(不与点A重合);
③连接
.
问题:
(1)说明
平分
的理由;
(2)判断
与
的数量关系,并说明理由.(提示:为说明方便,可直接在尺规作图后的图中添加字母或线段)
如图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
①作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
②在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
③连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40b3e9a99b5b8258baab51f66d1a48ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/19/2b6666fc-7930-419a-bd13-e82f0063870e.png?resizew=106)
问题:
(1)说明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
(2)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cfc2771aa0d5b97d2297f8a26a6f6b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86a2db6311e228ed33b6c71d0a5918cf.png)
您最近一年使用:0次
2 . 如图,
是
的半径,
为
的切线.
(1)尺规作图:用无刻度的直尺和圆规完成以下作图:
①延长
交
于点
;
②过点
作直线
的垂线交
于点
;
③连接
.(不写作法,保留作图痕迹)
(2)在(1)的条件下,连接
,判断
与
的数是关系并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/11/3d517c29-1779-4c36-97e9-58b5c37f2f28.png?resizew=172)
(1)尺规作图:用无刻度的直尺和圆规完成以下作图:
①延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
②过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
③连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
(2)在(1)的条件下,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d22df2977de56cc69be0c1e847653d7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac3c1375c64dceef45846308a418cf7f.png)
您最近一年使用:0次
2023-05-30更新
|
126次组卷
|
3卷引用:2023年河南省驻马店市确山县中考三模数学试题
3 . 如图,在
中,D是边
上的一点,
.
平分
,交
于点E,连接
(不写作法,保留作图痕迹);
(2)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f5fc4ad65b723b6a8da4c8dac154e6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ee1ee0e54adcc43004ae6c6946ef056.png)
您最近一年使用:0次
2023-03-22更新
|
356次组卷
|
6卷引用:2023年广东省郁南县宋桂镇初级中学初中数学学业水平考试模拟试卷
2023年广东省郁南县宋桂镇初级中学初中数学学业水平考试模拟试卷 (已下线)2023年河南省中考数学真题变式题16-19题(已下线)期末模拟预测卷01(测试范围:七下全册)-2022-2023学年七年级数学下学期期中期末考点大串讲(北师大版)广东省揭阳市榕城区2022-2023学年七年级下学期期末数学试题广东省江门市第一实验学校2023-2024学年八年级第上学期第一次月考数学试题广东省佛山市顺德区拔萃实验学校2023-2024学年八年级下学期月考数学试题
4 . 如图,
是等边三角形,
是
边上的中线.
操作与实践:(1)利用尺规作
的平分线
,交
于点E(要求:尺规作图,保留作图痕迹,不写作法,标明字母);
猜想与证明:(2)试探究线段
与
的数量关系,并证明结论.
![](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)
操作与实践:(1)利用尺规作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
猜想与证明:(2)试探究线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/15/faaf856b-8108-4f79-9e1f-bed7d89e6eec.png?resizew=133)
您最近一年使用:0次
2023九年级·全国·专题练习
5 . 如图,四边形
是正方形,点E,K分别在
,
上,点G在
的延长线上,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/28/7c6ea07d-dbb7-4b5f-a63b-cfe28703f506.png?resizew=124)
(1)求证:①
;
②
;
(2)尺规作图:以线段
,
为边作出正方形
(要求:只保留作图痕迹,不写作法和证明);
(3)连接(2)中的
,猜想并写出四边形
是怎样的特殊四边形,并证明你的猜想.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e4f9319acaf7a9292e861ad0239e5cc.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/28/7c6ea07d-dbb7-4b5f-a63b-cfe28703f506.png?resizew=124)
(1)求证:①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c6bbde2a6aa141f91db418a950b7d53.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b8cbde98d09c06d2cc5481c6a8fbad8.png)
(2)尺规作图:以线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2257da1e2425f2ea9ac7440f52659ff.png)
(3)连接(2)中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88ac28c7adade476df476c2bf90a8416.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35da6d44f69897574e057fc255622580.png)
您最近一年使用:0次
名校
6 . 如图1,在
中,D,E分别是边
上的点.对“三角形中位线定理”逆向思考,可得以下3则命题:
I.若D是
的中点,
,则E是
的中点;
II.若
,
,则D,E分别是
的中点;
III.若D是
的中点,
,则E是
的中点.
他的思考方法如下:在图2中使用尺规作图作出满足命题I条件的点E,从而直观判断E不一定是
的中点.
小明尺规作图的方法步骤如下:
①在图2中,作边
的垂直平分线,交
于点M;
②在图2中,以点D为圆心,以BM的长为半径画弧与边AC交与点E和
;
请你在图2中完成以上作图.
(2)小明通过对命题II和命题III的思考,发现这两个命题都是真命题,请你从这两个命题中选择一个,并借助于图1进行证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dec2ca6438c82b43f746057d8129885.png)
I.若D是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/950e82a0f9712457f2dd9f8a93f8a217.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
II.若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d021981c03e75b1a246d899dcc64656.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/950e82a0f9712457f2dd9f8a93f8a217.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dec2ca6438c82b43f746057d8129885.png)
III.若D是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d021981c03e75b1a246d899dcc64656.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
他的思考方法如下:在图2中使用尺规作图作出满足命题I条件的点E,从而直观判断E不一定是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
小明尺规作图的方法步骤如下:
①在图2中,作边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
②在图2中,以点D为圆心,以BM的长为半径画弧与边AC交与点E和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3b1a5427d8ff23df0f3ec194756c84c.png)
请你在图2中完成以上作图.
(2)小明通过对命题II和命题III的思考,发现这两个命题都是真命题,请你从这两个命题中选择一个,并借助于图1进行证明.
您最近一年使用:0次
2023-07-04更新
|
65次组卷
|
4卷引用:2023年河南省南阳市唐河县四校联考中考模拟数学模拟试题(三)
2023年河南省南阳市唐河县四校联考中考模拟数学模拟试题(三)河南省平顶山市汝州市2022-2023学年八年级下学期期末数学试题(已下线)北京市第四中学2023-2024学年八年级下学期期中数学试题(已下线)第四章 平行四边形能力提升测试卷-2023-2024学年八年级数学下册《知识解读·题型专练》(浙教版)
名校
7 . 如图,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/14/f14485c8-c1b7-4893-bed2-ad445bb38b25.png?resizew=191)
(1)在
上方求作一点
,使得
,且
,连接
(要求:尺规作图,保留作图痕迹,不写作法).
(2)在(1)的条件下,连接
、
、
,若
,
,求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46354bb0d4f2e0b785d137c8c543d1d8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/14/f14485c8-c1b7-4893-bed2-ad445bb38b25.png?resizew=191)
(1)在
![](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/d59f9a4fe996045c2e1adb8caa06c1c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06a2ab6940dca62be1f3b2b5f8531990.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(2)在(1)的条件下,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82773737609e65dea3c5c67099f1b10d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3acee288e75061ac72203b09fce29904.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79cd9d0d73549e2944578f3513631ce5.png)
您最近一年使用:0次
名校
8 . 在学习等腰直角三角形的过程中,小邓同学遇到了一个问题:在等腰直角
中,
,
,点D为线段
上任意一点,试说明
,
,
之间的数量关系.小邓的思路是:首先过点C作
的垂线,再构造与
全等的三角形,从而转化
,
,使问题得到解决.请根据小邓的思路完成下面的作图与填空:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/30/53636865-6d7f-433e-9d28-c6b5ec2ab7bb.png?resizew=155)
尺规作图:过点C作
的垂线
,在
上方的直线
上截取
,连接
,
(用基本作图,保留作图痕迹,不写作法、结论)
证明:∵
为等腰直角三角形,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
∴
,
∵![](https://staticzujuan.xkw.com/quesimg/Upload/formula/531d6f90f144551a35d494b1fe7d2b89.png)
∴ ①
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/088d6db608daa64794b05150e533f992.png)
在
和
中,
,
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c9d742e4a621c96282d92aca938af4a.png)
∴
, ③
∵![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c494073a8885ccc64e67a82960ca6ba2.png)
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12e98befaa51ebc7ff54c27bac2fe577.png)
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/597221bdc3fdacf0b653e447330df351.png)
在
中,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b377c8de5d747d1fc629e684de77c148.png)
在
中,
, ④
又∵![](https://staticzujuan.xkw.com/quesimg/Upload/formula/494bf14f8369edcb5ba24413e91fd473.png)
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bc3a243f054922cbdee701b9cf0b91.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.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/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/30/53636865-6d7f-433e-9d28-c6b5ec2ab7bb.png?resizew=155)
尺规作图:过点C作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7322382eecd41e1348226680a830da9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4b5c7adb15ace2f3b94518c13fe3a48.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/531d6f90f144551a35d494b1fe7d2b89.png)
∴ ①
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/088d6db608daa64794b05150e533f992.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54fb6e81fee5674c3e26a65e58cc506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e18c01a354ddf9f165d27ba035c773b5.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c9d742e4a621c96282d92aca938af4a.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4e363bfd418579e6229230df034bbc.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c494073a8885ccc64e67a82960ca6ba2.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12e98befaa51ebc7ff54c27bac2fe577.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/597221bdc3fdacf0b653e447330df351.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1097ba266ccd9a0cebe03cfba7cd638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/597221bdc3fdacf0b653e447330df351.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b377c8de5d747d1fc629e684de77c148.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a11d39173fcd69bd561391958be2d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc60f2fd9c91293a743111539202a169.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/494bf14f8369edcb5ba24413e91fd473.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bc3a243f054922cbdee701b9cf0b91.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4c8710634c8b7aa5578682a1b8504c2.png)
您最近一年使用:0次
2023-03-28更新
|
522次组卷
|
2卷引用:重庆市沙坪坝区第八中学校2022-2023学年九年级下学期3月月考数学试题
名校
9 . 如图,在
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/8d5015b4-478e-4229-9ce2-e9c9efaa0184.png?resizew=156)
(1)尺规作图:作
的平分线
,交
于点
;作线段
的垂直平分线交AC于点
,交
于点
;连接
,
(不写做法,保留作图痕迹);
(2)在(1)的条件下,证明:
.
证明:∵GF垂直平分线段
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8520a21b909d04f763d0f61dd74bc158.png)
∴
,①
∵
平分
,
∴② ,
∵在
和
中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c5c2a9b034e26afedba99a1c79e3ff9.png)
∴
,
∴④ ,
∴
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8520a21b909d04f763d0f61dd74bc158.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/8d5015b4-478e-4229-9ce2-e9c9efaa0184.png?resizew=156)
(1)尺规作图:作
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06e322e0c87479bba874db9ae9ba36b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
(2)在(1)的条件下,证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9d6125a8806ff6923c3e4ccbdf1de5.png)
证明:∵GF垂直平分线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8520a21b909d04f763d0f61dd74bc158.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bd02aa31b79fc5929f2c29d917810c4.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
∴② ,
∵在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147789d0ff172722271b095568f58a88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9e1592afb8b7e327eddeaee2a8b35e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c5c2a9b034e26afedba99a1c79e3ff9.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95317a39e3ab6804ae2fb522b594f75c.png)
∴④ ,
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9d6125a8806ff6923c3e4ccbdf1de5.png)
您最近一年使用:0次
10 . 阅读下列材料,并回答问题.
[材料]自从《义务教育数学课程标准(2022年版)》实施以来,九年级的龙老师增加了一个习惯,就是在每个新章节备课时都会查阅新课标,了解该章知识的新旧课标的变化,并在上课时告诉学生.他通过查阅新课标获悉:切线长定理由“选学”改为“必学”,并新增“会过圆外的一个点作圆的切线”.在学习完《切线的性质与判定》后,龙老师布置了一道课外思考题:“已知:如图,
及
外一点
.求作:直线
,使
与
相切于点
”.班上小岩同学所在的学习小组经过探索,给出了如下的一种作图方法:(1)连接
,以
为圆心,
长为半径作大圆
;(2)若
交小圆
于点
,过点
作小圆
的切线与大圆
交于
两点(点
在点
的上方);(3)连接
交小圆
于
,连接
,则
是小圆
的切线.
[问题]
(1)请问小岩同学所在的学习小组提供的作图方法是否正确?请你按照步骤完成作图(尺规作图,保留作图痕迹),并说明理由.
(2)延长
交大圆
于
,连接
,若
,
,求
的长.
[材料]自从《义务教育数学课程标准(2022年版)》实施以来,九年级的龙老师增加了一个习惯,就是在每个新章节备课时都会查阅新课标,了解该章知识的新旧课标的变化,并在上课时告诉学生.他通过查阅新课标获悉:切线长定理由“选学”改为“必学”,并新增“会过圆外的一个点作圆的切线”.在学习完《切线的性质与判定》后,龙老师布置了一道课外思考题:“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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.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/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
[问题]
(1)请问小岩同学所在的学习小组提供的作图方法是否正确?请你按照步骤完成作图(尺规作图,保留作图痕迹),并说明理由.
(2)延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/167d31eb8432b5c0364316e5048c23dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9774f83067ed956a551bc41adcce0469.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e9344303efb0541eb449d782ad2b488.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/167d31eb8432b5c0364316e5048c23dd.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/1/15796e79-9c02-4fa8-9a66-ae1ac74ff406.png?resizew=208)
您最近一年使用:0次
2023-02-27更新
|
249次组卷
|
2卷引用:福建省龙岩市2022-2023学年九年级上学期期末数学质量检测