(1)如图1,将一长方形纸片
沿着
、
折叠(点
在线段
上,点
在线段
上),且
,折痕
与
平行吗?请说明理由.
![](https://img.xkw.com/dksih/QBM/2021/5/8/2716531430711296/2768467400630272/STEM/aec97877-ca7b-4963-afd1-f3d7d5ed52ef.png?resizew=569)
(2)如图2,将一长方形纸片
沿着
、
折叠(点
、
在线段
上),设
,
,当
与
平行时,
与
有什么数量关系?请说明理由.
(3)如图3,将一长方形纸片
沿着
折叠(点
在线段
上),不借助其他工具,请设计一个折纸方案,折叠纸片,使得边
与
平行.请在图3中画出折叠后的示意图,并简述你的折纸方案.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.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/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c550750e64cf6d4e68448d84bc66072a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://img.xkw.com/dksih/QBM/2021/5/8/2716531430711296/2768467400630272/STEM/aec97877-ca7b-4963-afd1-f3d7d5ed52ef.png?resizew=569)
(2)如图2,将一长方形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3160d33de228937b8a691519fced22e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8da4177449887fa1e3c98fe81570b7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1eba8ef753df3569875282d12342c149.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8ba89e83329983cfadbfcdda151aaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
(3)如图3,将一长方形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1eba8ef753df3569875282d12342c149.png)
更新时间:2021-07-20 20:04:15
|
相似题推荐
解答题-证明题
|
适中
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名校
【推荐2】按图填空, 并注明理由
已知: 如图, ∠1=∠2, ∠3=∠E. 求证: AD∥BE
![](https://img.xkw.com/dksih/QBM/2017/6/9/1705351805902848/1709337236144128/STEM/97dd1617ec65407f9157880a6b1f86f0.png?resizew=166)
证明: ∵∠1 = ∠2 (已知)
∴ ∥ ( )
∴ ∠E = ∠ ( )
又∵ ∠E = ∠3 ( 已知 )
∴ ∠3 = ∠ ( 等量代换 )
∴ ∥ ( 内错角相等,两直线平行 )
已知: 如图, ∠1=∠2, ∠3=∠E. 求证: AD∥BE
![](https://img.xkw.com/dksih/QBM/2017/6/9/1705351805902848/1709337236144128/STEM/97dd1617ec65407f9157880a6b1f86f0.png?resizew=166)
证明: ∵∠1 = ∠2 (已知)
∴ ∥ ( )
∴ ∠E = ∠ ( )
又∵ ∠E = ∠3 ( 已知 )
∴ ∠3 = ∠ ( 等量代换 )
∴ ∥ ( 内错角相等,两直线平行 )
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解答题-问答题
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适中
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【推荐1】△ABC中,∠ACB=90°,AC=BC=6,M点在边AC上,且CM=2,过M点作AC的垂线交AB边于E点.动点P从点A出发沿AC边向M点运动,速度为每秒1个单位,当动点P到达M点时,运动停止.连接EP,EC.在此过程中,设P运动的时间为t秒,回答下列问题:
![](https://img.xkw.com/dksih/QBM/2014/12/23/1573775864684544/1573775870558208/STEM/bd9127304b304475adbd29c9c0fdeb69.png)
(1)AP= ,PC= (用含t的代数式表示)
(2)当t为何值时,△EPC的面积为10?
(3))将△EPC沿CP翻折后,点E的对应点为F点,当t为何值时,PF∥EC?
![](https://img.xkw.com/dksih/QBM/2014/12/23/1573775864684544/1573775870558208/STEM/bd9127304b304475adbd29c9c0fdeb69.png)
(1)AP= ,PC= (用含t的代数式表示)
(2)当t为何值时,△EPC的面积为10?
(3))将△EPC沿CP翻折后,点E的对应点为F点,当t为何值时,PF∥EC?
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解答题-应用题
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【推荐2】在一次数学探究活动中,小明用两条直线把平行四边形
分割成四个部分,使含有一组对顶角的两个图形全等.
(2)根据小明的分割方法,你认为把平行四边形分割成满足以上全等关系的直线有______组;由上述实验操作过程,你发现小明所画的两条直线的主要特点是______.
(3)拓展延伸:将一张平行四边形的纸片
沿过对角线
的中点
的直线
折叠,折痕交边
、
于点
、
,点
落在点
处,点
落在点
处.设
交
于点
,
分别交
、
于点
、
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)根据小明的分割方法,你认为把平行四边形分割成满足以上全等关系的直线有______组;由上述实验操作过程,你发现小明所画的两条直线的主要特点是______.
(3)拓展延伸:将一张平行四边形的纸片
![](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/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.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/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54fee2afdacb11a6d025578bcaf576d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e105760638b22b26ff8bec4354255e4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86556a0785f950c27832a2fe02e7bcc8.png)
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解答题-问答题
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【推荐3】数学活动:折纸中的数学
【知识背景】
我们在第四章《几何图形初步》中学习了角的平分线,并会用折纸的方法作角平分线.
如图4.3﹣11是教材第135页的探究,将纸片折叠使
与
重合,
是折痕,此时
与
重合,所以
,射线
是
的平分线.
【知识初探】
(1)如图1,点P,Q分别是长方形纸片
的对边
上的点,连结
,将
和
分别对折,使点A,B都分别落在
上的
和
处,点C落在
处,分别得折痕
,则
的度数是________;
【类比再探】
(2)如图2,将长方形
纸片分别沿直线
折叠,使点A,B分别落在点
,
处,
和
不在同一条直线上,且被折叠的两部分没有重叠部分.
①若
,求
的度数;
②若
,求
的度数(用含α的式子表示);
【拓展探究】
(3)将长方形
纸片分别沿直线
折叠,使点A,B,C分别落在点
,
,
处,
和
不在同一条直线上,且被折叠的两部分有重叠部分,如图3,若
,请直接写出
的度数(用含α的式子表示).
【知识背景】
我们在第四章《几何图形初步》中学习了角的平分线,并会用折纸的方法作角平分线.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/29/8ddced38-d17f-42bc-9510-0294f9b5deb2.png?resizew=363)
如图4.3﹣11是教材第135页的探究,将纸片折叠使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1be602a29cad9e1fb71072174e77eaf2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f59bf3d32bf5eef67c59d674e01d26f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b22a1e95e9685a94178d4ff36d4c994.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5e5d3b3f0c55131292b98a884beba6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24f56aaf35f7816f6a7bdd45396987e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5195789e8dfdcbdde9dccbc594e55fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b22a1e95e9685a94178d4ff36d4c994.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b8a8cf65e4baa874af0cc88090fc3d.png)
【知识初探】
(1)如图1,点P,Q分别是长方形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a13e1565e5977304abe033ea80742f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e430f13f42cf2d44aa0f0e20b959684f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67bbe27d6b97eec6b9e79555556a5216.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37c65f4967577366d22d3ce9c1d21c6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e430f13f42cf2d44aa0f0e20b959684f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bde9258da29e3517635b1c7ef239edf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3998da44d274e5751d357beb1fa15a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713877f832ddbfc9d52bd9902cda13b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5174b80e12ddeaf0088c5eced306b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c504fdd7161212700a099b9cf5cfdd12.png)
【类比再探】
(2)如图2,将长方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5174b80e12ddeaf0088c5eced306b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bde9258da29e3517635b1c7ef239edf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3998da44d274e5751d357beb1fa15a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5500e5879706c71af3969dfbe60df493.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe1c7bf0db243814ec7ac81eab3fa464.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/898115235486d96a593ca1c40cdad536.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c504fdd7161212700a099b9cf5cfdd12.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6df969eea82f10fca8af0225a4de6ea1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c504fdd7161212700a099b9cf5cfdd12.png)
【拓展探究】
(3)将长方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5174b80e12ddeaf0088c5eced306b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bde9258da29e3517635b1c7ef239edf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3998da44d274e5751d357beb1fa15a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713877f832ddbfc9d52bd9902cda13b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5500e5879706c71af3969dfbe60df493.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe1c7bf0db243814ec7ac81eab3fa464.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ead6de2e6478bd565acb78f72433676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c504fdd7161212700a099b9cf5cfdd12.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/29/a0ed90b1-f3bd-4776-95dd-cdac8d21533e.png?resizew=523)
您最近一年使用:0次