如图,在▱ABCD中,过点D作DE⊥AB于点E,点F在边CD上,DF=BE.求证:四边形BEDF是矩形.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/17/e5df098e-dbe1-4fed-bd76-45d5666c56ad.png?resizew=157)
18-19八年级上·重庆·期中 查看更多[9]
重庆实验学校-2018-2019学年八年级第一学期期中数学试题福建省厦门竹坝中学2017-2018学年八年级(下)期中数学试题华东师大版八年级数学下册19.1.2 矩形的判定同步练习河北省保定市高阳县2020-2021学年八年级下学期期末数学试题重庆市綦江区通惠中学2020-2021学年八年级下学期第二次定时作业数学试题山西省临汾市部分学校2021-2022学年八年级下学期学科素养形成练习(三)数学试题广东省汕头市潮阳区2021-2022学年八年级下学期期中检测数学试卷广东省岭南师范学院附属中学、湛江市东方实验学校 2022-2023学年八年级下学期期中数学试题江西省九江市2022-2023学年九年级上学期期末数学试题
更新时间:2019-06-19 17:30:21
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相似题推荐
解答题-证明题
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适中
(0.65)
【推荐1】如图,在平行四边形
中,点E是边
的中点,连接
并延长,交
的延长线于点F,连接
,
.
(1)求证:
;
(2)当四边形
是矩形时,若
,求
的度数.
![](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/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/28/6c93c6ca-6952-4013-905d-fa0461f4d8ad.png?resizew=177)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3080269a5b7b8b1eb9f3a3edadfe45e9.png)
(2)当四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcca8b9ba7a9fdd7d18ce9c1e86d2cd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9613b4a095f5fec32e70ef5ec6620ac2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c543c3ddc3723fde6bbfca3ea3b921b.png)
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名校
【推荐2】【教材呈现】如图是华师版八年级下册数学教材第77页的部分内容.
平行四边形的性质定理3 平行四边形的对角线互相平分.
我们可以证明这个结论.
已知:如图,▱ABCD的对角线AC和BD相交于点O.
求证:OA=OC,OB=OD.
【性质应用】
(2)如图②,▱ABCD的对角线AC、BD相交于点O,EF过点O且与AD、BC分别相交于点E、F,求证:OE=OF
(3)连结AF,若EF⊥AC,△ABF周长是15,则▱ABCD的周长是______.
平行四边形的性质定理3 平行四边形的对角线互相平分.
我们可以证明这个结论.
已知:如图,▱ABCD的对角线AC和BD相交于点O.
求证:OA=OC,OB=OD.
【性质应用】
(2)如图②,▱ABCD的对角线AC、BD相交于点O,EF过点O且与AD、BC分别相交于点E、F,求证:OE=OF
(3)连结AF,若EF⊥AC,△ABF周长是15,则▱ABCD的周长是______.
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解答题-证明题
|
适中
(0.65)
【推荐1】如图,将平行四边形
的边
延长至点
,使
,连接
,
,
,交
于点
.
(1)求证:
;
(2)连接
,若
,求证:四边形
是矩形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4e92f48e9bfe12d145f7d2a2f0360d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/5/3dfb6c4b-cad6-47fe-8be2-d7ac29bd905b.png?resizew=150)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f5dda9baf8ff50d4bf87304e062d46e.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b7f35738524dcb80969b063f8966b4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adfe2a58326612fcabd34fd4402a66ee.png)
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【推荐2】如图,
是
的外接圆,
为直径,
的平分线交
于点
,过点
的切线分别交
,
的延长线于点
,
,连接
.
![](https://img.xkw.com/dksih/QBM/2020/2/24/2406151585931264/2406650500374528/STEM/914f7bee-739c-4ca0-8aa2-219ae5f90430.png)
(1)求证:
;
(2)若
,
,求
的半径.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/2020/2/24/2406151585931264/2406650500374528/STEM/914f7bee-739c-4ca0-8aa2-219ae5f90430.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac559a1a89bfb16e1c44cdd7ad2f2bbd.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93bc4c9dd737193f7acce692b23500d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
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