如图,在四边形ABCD中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/19/50070a51-ee54-4be8-8f4e-b775dddc95ec.png?resizew=235)
(1)用直尺和圆规作
的角平分线AF,分别交BD、BC于点E、F;(保留作图痕迹,不写作法),
(2)求证:
(请把下列证明过程及理由补充完整)
证明:∵AF平分
(已知)
∴
___________(角平分线的定义)
∵
(已知)
∴
__________(_________________)
∴______=______(等量代换)
∴
(________________)
∵
(已知)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6c34067dff25379792af9a45f720303.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/19/50070a51-ee54-4be8-8f4e-b775dddc95ec.png?resizew=235)
(1)用直尺和圆规作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ac85be72fc51ef4c90de7e00c5556cd.png)
证明:∵AF平分
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad75bdd17013af544fc97ab1dcecb873.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dceb5cc71fc50f20649f6b9535fd914.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad75bdd17013af544fc97ab1dcecb873.png)
∴______=______(等量代换)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1c9ea68cd9659d200587026b9c6ac4c.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ac85be72fc51ef4c90de7e00c5556cd.png)
更新时间:2022-07-07 06:03:18
|
相似题推荐
解答题-问答题
|
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【推荐1】如图,在
中,点
是边
的中点,过点
作直线
使
,交
的延长线于点
.试说明
的理由.
![](https://img.xkw.com/dksih/QBM/2021/6/25/2750655025946624/2759923754770432/STEM/ab67f6e9-7bb6-424c-8fd2-e6211fe40a5d.png)
解:因为
(已知),
所以
( )
因为点
是边
的中点,
所以
在
和
中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02e7adeab91ec2d3838774c29461642.png)
所以
( )
所以
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da714ecb60f172613ec4cfbf5dc2c10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a763381e4a9e6ac9d9c1df51122570f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/503668fcc7878c81c664c13fa47cba29.png)
![](https://img.xkw.com/dksih/QBM/2021/6/25/2750655025946624/2759923754770432/STEM/ab67f6e9-7bb6-424c-8fd2-e6211fe40a5d.png)
解:因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79e6cd0fb901b4bb1655175ae4a97565.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c0c46783b77cce2bd4b45b9acc61884.png)
因为点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
所以
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db5e1441a49e782ff0ef46e776cde06a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b265d121f9ebc13671a5719604476a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02e7adeab91ec2d3838774c29461642.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e73670d10fb713b2beb4737bc5ad28cb.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/503668fcc7878c81c664c13fa47cba29.png)
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解答题-证明题
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【推荐2】如图,在
中,
,
分别平分
,
,过
作直线平行于
,交
,
于
,
,求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05ff441308ef4b2e57394fc3138cd361.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fabb884dc5f9609de491245463bbe9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05ff441308ef4b2e57394fc3138cd361.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/18/3140c663-6772-4b89-b68b-6d5034240c90.png?resizew=135)
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解答题-作图题
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【推荐1】在学习平行四边形后,小函进行了拓展性研究,她发现,平行四边形
中,在
边上截
,连接
,作
的角平分线交
于点E,则
.她的解决思路是通过证明两条线段所在的四边形是平行四边形得出结论.请根据她的思路完成以下作图和填空;
(1)用直尺和圆规,在
边上截
,连接
,作
的角平分线
,交
于点E(只保留作图痕迹).
(2)已知:如图,四边形
是平行四边形,
,
平分
,交
于点E.求证:
.
是平行四边形,
∴
,
,
,
∴
___①___,
∵
平分
,
∴
___②___,
∴
,
∴
,
∵
,
∴
___③___,
∴
___④___,
∴
,
∴四边形
是平行四边形(___⑤___),
∴
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfa8a9b14da8a472a8855449f1160b84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7c581dab991aeadf06d972e47673ea8.png)
(1)用直尺和圆规,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfa8a9b14da8a472a8855449f1160b84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(2)已知:如图,四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d3cd8fbcd9eb594adb8367795d444d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7c581dab991aeadf06d972e47673ea8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c220eadc312101e2fb89dfe920f7b30d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d2530e7023b2345c651e8f53629ff1.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8ec5a6d46df6c070e239ae6d642a54.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6b41d4070854edfaa24071137b314cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8ec5a6d46df6c070e239ae6d642a54.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60faf66a8aca6cff908cb939b5a4e564.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df1ac3ab8d3ce5e61fd2f89761f80976.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95adbf026e5ad4ce6f123e5e0b89da7d.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4f76e37d6e6b182896ccaaa187cfe07.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/189d4911005c20ea6d155bb7a9d28a96.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c931bbba4e02a2ad4584311896738f33.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7c581dab991aeadf06d972e47673ea8.png)
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解答题-作图题
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【推荐2】折叠如图所示的直角三角形纸片ABC,使点C落在AB上的点E处,折痕为AD(点D在BC边上),用直尺和圆规画出折痕AD.(保留作图痕迹,不写作法).
![](https://img.xkw.com/dksih/QBM/2020/11/19/2596311330717696/2598638303395840/STEM/315e4843f3384a54b4e10751a901197b.png?resizew=179)
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名校
【推荐1】下面是小东设计的“作三角形一边上的高”的尺规作图过程.
(2)完成下面的证明.
证明:连接
.
∵
,
,
∴
是线段
的垂直平分线( )(填推理的依据) ,
已知:.
求作:边上的高
.
作法:如图1,
①以点A为圆心,适当长为半径画弧,交直线于点M,N;
②分别以点M,N为圆心,以大于的长为半径画弧,两弧相交于点P(不同于点A);
③作直线交
于点D. 所以线段
就是所求作的
的边
上的高.
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/acec3a658201148bb39a473af2b6f961.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1039601edd7326b628a3201a3d4af948.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eee4f934a850682f0a7a6c7206724c1f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
∴于点D,
即线段为
的边
上的高.
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解答题-作图题
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【推荐2】如图1,两条交叉马路
,
中间区域建有A,B两个温室花房.现要在两条马路
,
之间的空场处建鲜花交易中心P,使得交易中心P到两条马路
,
的距离相等,且到两个温室花房A,B的距离也相等.如何确定交易中心P的位置?如图2,利用尺规作图求作点P(不写作法,保留作图痕迹).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3369e0ea90e8d5cf4b6b3c45c0fd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e9f7d1272b7344346b58b660aa260a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3369e0ea90e8d5cf4b6b3c45c0fd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e9f7d1272b7344346b58b660aa260a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3369e0ea90e8d5cf4b6b3c45c0fd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e9f7d1272b7344346b58b660aa260a.png)
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【推荐1】如图,抛物线
经过
,
两点,点
是
轴左侧且位于
轴下方抛物线上一动点,设其横坐标为
.
(1)直接写出抛物线的解析式;
(2)将线段
绕点
顺时针旋转
得线段
(点
是点
的对应点),求点
的坐标,并判断点D是否在抛物线上;
(3)过点
作
轴交直线
于点
,试探究是否存在点
,使
是等腰三角形?若存在,求出点
的值;若不存在,说明理由.
![](https://img.xkw.com/dksih/QBM/2021/2/4/2650679027818496/2652049897783296/STEM/9294a8de-5c5e-416f-9d6e-6cba69ee7174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22106baba401cfaef881253e49c3c777.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76943522d2b99a6275c7b4d54dd7f31a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4bc333cee094e9dd8f1f3ff86adc95f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ce066003c0a1f0879cbca2f32802e9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(1)直接写出抛物线的解析式;
(2)将线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
(3)过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ce066003c0a1f0879cbca2f32802e9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea3a3db6d96518255f96ad7fc1ac98f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68ae0df0b9934dd820e797e501e7074b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://img.xkw.com/dksih/QBM/2021/2/4/2650679027818496/2652049897783296/STEM/9294a8de-5c5e-416f-9d6e-6cba69ee7174.png)
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【推荐2】综合实践课上,小明所在的小组要测量学校到公路的距离.如图,
为东西走向的一条公路,
是小明所在的学校,小明在
点处测得学校
在他的北偏东
方向上,沿正东方向4千米后到达
处,此时学校
在他的北偏西
方向上,求学校到公路
的最短距离.(结果精确到0.1千米,参考数据:
,
,
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
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