如图所示,已知
于点
,
于点
,
,说明:
平分
.
下面是推理过程,请你将其补充完整,
于点
,
于点
(已知)
所以![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a2b9fa58d9c24e6477c331661dcc82a.png)
所以AD//EG( )
所以
( )
=
(两直线平行,同位角相等)
又因为
(已知),
所以
( )
所以AD平分∠BAC( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8c13ab7f17263c4e6163d960f1c5060.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e0f86566770c9a240ebef8bd232cc9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
下面是推理过程,请你将其补充完整,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8c13ab7f17263c4e6163d960f1c5060.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a2b9fa58d9c24e6477c331661dcc82a.png)
所以AD//EG( )
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/605f2976297a0deaa1602ef09d6a5afa.png)
又因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e0f86566770c9a240ebef8bd232cc9f.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba02910a01689f636c71116e96dfdf33.png)
所以AD平分∠BAC( ).
19-20七年级上·山西临汾·期末 查看更多[6]
山西省临汾市翼城县2019-2020学年七年级上学期期末数学试题福建省上杭县第四中学2021-2022学年七年级下学期5月综合训练数学试题重庆市2022-2023学年七年级上学期期末数学试题(已下线)上海七年级下期中真题精选(常考60题专练)(已下线)上海市七下期中真题精选(压轴大题50题7个考点分类专练)-2023-2024学年七年级数学下学期期中考点大串讲(沪教版)广东省汕头市潮南区龙岭中英文学校2023-2024学年七年级下学期期中数学试题
更新时间:2021-02-21 19:13:48
|
【知识点】 根据平行线判定与性质证明
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解答题-证明题
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较易
(0.85)
名校
【推荐1】已知:如图,点D、E、F、G都在△ABC的边上,EF∥AC,且∠1+∠2=180°.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/8/97590be2-570a-4824-8b93-59b575788608.png?resizew=265)
(1)求证:AE∥DG;
(2)若EF平分∠AEB,∠C=40°,求∠BDG的度数.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/8/97590be2-570a-4824-8b93-59b575788608.png?resizew=265)
(1)求证:AE∥DG;
(2)若EF平分∠AEB,∠C=40°,求∠BDG的度数.
您最近一年使用:0次
解答题-证明题
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较易
(0.85)
【推荐2】如图,已知
于点G,请判断
与
是否垂直,请补全说理过程及依据.
(已知)
所以
( )
又
(已知)
可得
( )
所以
( )
所以
( )
因为
于点G
所以![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9017dc1f04f6725bc6ee3fb631ed9619.png)
所以![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a20cb14fea4a7cad4b7775a3dd67df9.png)
所以
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9cafbfb3f7844d1073e7f3b6d9643986.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c436f108fd4921dae15ecff19270237e.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1587e90b7add2a2550326276b4c9ebd2.png)
又
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
可得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50b1017b62a3cccbed25c6287241a9c9.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9656be9d72cf0b93d4da2432e1fdf291.png)
因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3122dca7febe1c67d2d1d53724dd7070.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9017dc1f04f6725bc6ee3fb631ed9619.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a20cb14fea4a7cad4b7775a3dd67df9.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a77e3c1c236141d6118429fade0a9b9d.png)
您最近一年使用:0次