【问题情景】 通过作平行线来实现问题转化是我们常用到的方法.
如图1,在△ABC中,DE∥BC分别交AB于D,交AC于E.已知CD⊥BE,CD=2,BE=4,求BC+DE的值.我们可以过点D作BE的平行线(如图2),也可过点E作CD的平行线解决问题.
【问题解决】(1)请回答:BC+DE的值为 .
【类比探究】(2)如图3,已知▱ABCD和矩形ABEF,AC与DF交于点G,AC=BF=DF,参考上述思考问题的方法,求∠AGF的度数.
【迁移应用】(3)如图4,已知:AB、CD交于E点,连接AD、BC,AD=3
,BC=1.且∠B与∠D互为余角,∠A与∠C互为补角,则∠AED= 度,若CD=
,求AB的长.
如图1,在△ABC中,DE∥BC分别交AB于D,交AC于E.已知CD⊥BE,CD=2,BE=4,求BC+DE的值.我们可以过点D作BE的平行线(如图2),也可过点E作CD的平行线解决问题.
【问题解决】(1)请回答:BC+DE的值为 .
【类比探究】(2)如图3,已知▱ABCD和矩形ABEF,AC与DF交于点G,AC=BF=DF,参考上述思考问题的方法,求∠AGF的度数.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/13/6b350cde-ebf5-4c65-9ea6-801b88bc9bc2.png?resizew=521)
【迁移应用】(3)如图4,已知:AB、CD交于E点,连接AD、BC,AD=3
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e2031d209711b058f3d278ede3c1d33.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/13/4489b209-5acc-4419-b28f-04aff7829f22.png?resizew=203)
2020·内蒙古鄂尔多斯·二模 查看更多[2]
2020年内蒙古鄂尔多斯市东胜区九年级初中毕业升学二模数学试题(已下线)专题5.21 《相交线与平行线》几何模型之综合探究压轴题-2020-2021学年七年级数学下册基础知识专项讲练(人教版)
更新时间:2020-08-09 18:16:07
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】已知:如图,在Rt
中,∠ACB=90°,∠CAB=30°,P是AB边上任意一点,D是AB边的中点,连接CP,CD,并将PC绕点P逆时针旋转60°得到PE,连接AE.
(1)求证:CD=BC;
(2)①依题意补全图形;
②用等式表示线段PE与AE的数量关系,并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
(1)求证:CD=BC;
(2)①依题意补全图形;
②用等式表示线段PE与AE的数量关系,并证明.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/5/ee0eef20-d0f3-4e37-8697-eb9c6229062d.png?resizew=198)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】已知:如图,点A、B、C在同一直线上,AB=2,BC=1,分别以AB、BC为边,在AC同侧作等边△ABD和等边△BCE,分别联结AE、CD.
(1)找出图中的全等三角形(不添加辅助线),并证明你的结论.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/6/016c26ed-4887-4d34-9377-0ac64e578e51.png?resizew=141)
(2)线段AE与线段CD的关系是:AE CD(填>、=、<).AE与CD的夹角是: .
(3) △ABD固定不动,使△BCE绕着点B旋转,①这时(2)得出的结论还成立吗(不要求证明)?
②在旋转过程中,线段DC的长是变化的,它的变化范围是 .
(1)找出图中的全等三角形(不添加辅助线),并证明你的结论.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/6/016c26ed-4887-4d34-9377-0ac64e578e51.png?resizew=141)
(2)线段AE与线段CD的关系是:AE CD(填>、=、<).AE与CD的夹角是: .
(3) △ABD固定不动,使△BCE绕着点B旋转,①这时(2)得出的结论还成立吗(不要求证明)?
②在旋转过程中,线段DC的长是变化的,它的变化范围是 .
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,平行四边形
的对角线
,
相交于点O,
平分
,
,
.
是菱形;
(2)若
,
,求
的长.
![](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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e305fa6e419e4187ccecd395c9d05288.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/090c757c225b6961975c9610e3dbae56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d71e6ea7333dbc78d0a7b9bc3892f940.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】如图,在△ABC中,∠A=30°,∠ACB=105°,CD⊥AB于D,BC=2cm,求AC和AB的长.(结果保留二次根式)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/21/3ff62f50-e5ff-4458-9b69-3d0aa8d2cda4.png?resizew=114)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在
中,
,D是
的中点,E是
的中点,过点A作
交
的延长线于点F.
(1)求证:
;
(2)求证:四边形
是菱形;
(3)若
,求菱形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.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/880efdb2b4ac4861ad808e0162d082be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/6/08957fa0-99db-4861-a0e4-58e82b35f3f7.png?resizew=285)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c664d49c072d75a6ae408c36f8906691.png)
(2)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94a5a2949b3d520ed03d57126c7d4d8d.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b73c3579e72e954ea3e3a84d77c0f1c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94a5a2949b3d520ed03d57126c7d4d8d.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,在平行四边形ABCD中,∠ABC=60°,E、F分别在CD和BC的延长线上,AE∥BD,EF⊥BC, AG⊥BC,EF=
.求AG的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/29/f9e5b643-86ef-46a3-94f1-54eec0532218.png?resizew=202)
您最近一年使用:0次
解答题-作图题
|
适中
(0.65)
【推荐1】如图是由边长为1的小正方形组成的
网格.
的长.
(2)在图1中,仅用无刻度的直尺,画出一个格点P,使
,且点P在网格的内部.
(3)在图2中,仅用无刻度的直尺,画出一个点Q,使
,保留作图痕迹并简要说明作法.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46abf9fa0ac52e352dc0eec7a352d577.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(2)在图1中,仅用无刻度的直尺,画出一个格点P,使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/315978386ec21efcf06945ac2a9c1fbc.png)
(3)在图2中,仅用无刻度的直尺,画出一个点Q,使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba8a07607f35a3d25b9ecdf4a667945b.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,由32个边长为1的小正三角形组成的网格
中,请按要求画图,且所画格点三角形与格点四边形的顶点均不与点
,
,
,
重合.
(1)在图1中画一个格点四边形
,使点
,
,
,
分别落在边
,
,
,
上,
与
互相平分但不相等.
(2)在图2中画一个格点四边形
,使点
,
,
,
分别落在边
,
,
,
上,
与
互相平分且相等.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.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/8455657dde27aabe6adb7b188e031c11.png)
(1)在图1中画一个格点四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/389bc3f29c058067e06e0d0d2be399da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/438f34bc8b04e8c494b91306ac6fe352.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5dbfcff5c8b5d4e312a9247b2b8b0a4.png)
(2)在图2中画一个格点四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/389bc3f29c058067e06e0d0d2be399da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/438f34bc8b04e8c494b91306ac6fe352.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3171b3d11c6f4619e189677345357508.png)
![](https://img.xkw.com/dksih/QBM/2020/6/22/2490291257950208/2493168127295488/STEM/12d26067-9224-43d4-ae12-da8173477e0c.png)
您最近一年使用:0次