平行四边形ABCD中,对角线AC,BD相交于点O,若E、F是AC上两动点,E、F分别从A、C两点同时以1cm/s的相同的速度向C、A运动.
![](https://img.xkw.com/dksih/QBM/2018/4/11/1922024411537408/1922570435100672/STEM/78c1effd716b478f8bd188d55995a01d.png?resizew=138)
(1)四边形DEBF是平行四边形吗.说明你的理由;
(2)若BD=10cm,AC=16cm,当运动时间t为多少时,四边形DEBF为矩形.
![](https://img.xkw.com/dksih/QBM/2018/4/11/1922024411537408/1922570435100672/STEM/78c1effd716b478f8bd188d55995a01d.png?resizew=138)
(1)四边形DEBF是平行四边形吗.说明你的理由;
(2)若BD=10cm,AC=16cm,当运动时间t为多少时,四边形DEBF为矩形.
更新时间:2018-04-12 17:02:28
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相似题推荐
解答题-问答题
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适中
(0.65)
【推荐1】如图,在数轴上
点表示数
,
点表示数
,
表示
点和
点之间的距离,且
、
满足
数轴上有一动点
,从
点出发,以每秒2个单位长度的速度沿数轴向右匀速运动,设运动时间为
秒
,
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/17/0a002505-32e8-4773-8fdb-d56d649c8541.png?resizew=189)
(1)点
表示的数为 ,点
表示的数为 .
(2)点
表示的数 (用含
的代数式表示);
(3)当点
运动 秒时,点
和点
之间距离为4;
(4)若数轴上另有一动点
,同时从
点出发,以每秒1个单位长度的速度沿数轴向左匀速运动,当点
和点
之间距离为6时,求时间
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.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/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/779f296d12eba95b562bd985679df40c.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/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3facaf367445f959446b8728ebe34b3e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/17/0a002505-32e8-4773-8fdb-d56d649c8541.png?resizew=189)
(1)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(3)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(4)若数轴上另有一动点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
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名校
【推荐2】如图,在矩形
中,
边上有一点E,连接
,若
.
(1)求出
,
的长;
(2)有一点P从点A出发,以
的速度沿
向点D运动,有一点Q从点C出发,以
的速度沿
向点B运动,当点Q到达点B时,点P,Q同时停止运动,设点P的运动时间为x秒.
①
秒时,四边形
为平行四边形;
②
秒时,四边形
为矩形;
(3)有一点M从点D出发,以
的速度沿
向终点A运动,同时有一点N从点B出发,以
的速度沿射线
运动,当点M停止运动时,点N同时停止运动.设点M的运动时间为t秒,问t取何值时,以M,N,C,D为顶点的四边形是平行四边形.
![](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/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba14993e476b2f151d5b15a171299072.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/1/00f88358-7ee5-4e5e-9f70-7ffb6e0afa9f.png?resizew=363)
(1)求出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(2)有一点P从点A出发,以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f240ecdd3d8ef73e6a7c3b9bc6b03409.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86df29fe8a12e816fb4a1fb783a6bbe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e3d635edbc25823cd7578e431dd8f0a.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe83f1ae7e5f05d8bed6bf6f42db0e7d.png)
(3)有一点M从点D出发,以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f240ecdd3d8ef73e6a7c3b9bc6b03409.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86df29fe8a12e816fb4a1fb783a6bbe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
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解答题-证明题
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【推荐1】如图,正方形ABCD的边长是3,点P是直线BC上一点,连接PA,将线段PA绕点P逆时针旋转
得到线段PE,在直线BA上取点F,使BF=BP,且点F与点E在BC同侧,连接EF,CF.
(1)如图①,当点P在CB延长线上时,求证:四边形PCFE是平行四边形;
(2)如图②,当点P在线段BC上时,四边形PCFE是否还是平行四边形,说明理由;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
(1)如图①,当点P在CB延长线上时,求证:四边形PCFE是平行四边形;
(2)如图②,当点P在线段BC上时,四边形PCFE是否还是平行四边形,说明理由;
![](https://img.xkw.com/dksih/QBM/2020/12/16/2615412027277312/2621664635781120/STEM/98f0463e-5922-41a6-94aa-ad0f10111226.png?resizew=382)
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解答题-证明题
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适中
(0.65)
【推荐2】如图,在直角三角形
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您最近一年使用:0次
解答题-证明题
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适中
(0.65)
【推荐2】如图,在矩形
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平分
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