名校
1 . 在学习三角形中位线定理时,小丽发现作以下辅助线能够证明三角形中位线定理.
已知:如图1,在
中,点D,E分别是边
的中点,连接
.
求证:
,
.
证明:(小丽的辅助线作法)延长
到F,使
,连接
…
(1)请在图1中画出小丽所说的辅助线,并补全三角形中位线定理的证明过程;
(2)三角形中位线定理应用:如图2,在梯形
中,
,点E,F分别是
的中点,则线段
之间的数量关系是 .
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/15/aced5448-5b28-4590-b581-3dfc3a1a296a.png?resizew=420)
已知:如图1,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5dc62e10004e73908091338362917da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c436f108fd4921dae15ecff19270237e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/950e82a0f9712457f2dd9f8a93f8a217.png)
证明:(小丽的辅助线作法)延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9a9618018d717926540d1452f76e44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bba9a009b7333329a38d775c55b8db5.png)
(1)请在图1中画出小丽所说的辅助线,并补全三角形中位线定理的证明过程;
(2)三角形中位线定理应用:如图2,在梯形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9b79c80cc81b5446dfac3ee97b03c03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87e449ef4ca245f6939855af28ecf3be.png)
您最近一年使用:0次
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2 . 已知:如图所示:点D,E分别是
的边
的中点.
求证:
,且
.
证明:延长
到点F,使EF=DE,连接
.∵
,∴四边形
是平行四边形,接着以下是排序错误的证明过程:①∴
;②
.即
;③四边形
是平行四边形;④
,且
.则正确的证明顺序应是( )
![](https://img.xkw.com/dksih/QBM/2022/12/17/3132770173321216/3141202387443712/STEM/f234c04730d34c219cc65a9b16e57a5d.png?resizew=192)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5dc62e10004e73908091338362917da.png)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d021981c03e75b1a246d899dcc64656.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/950e82a0f9712457f2dd9f8a93f8a217.png)
证明:延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/240537cd6eeb0a59e25dd46b8862f073.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0d0416d5bb09792ef8f90dacb6fbc99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94a5a2949b3d520ed03d57126c7d4d8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9baeb52b76c9330f21b5cb771049e694.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af897d6c002b65c63c8a66c52a4ce95c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f37ad8ed372ccd0c79542019c949da4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d15047493914a7de990b3b905875436.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d021981c03e75b1a246d899dcc64656.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/950e82a0f9712457f2dd9f8a93f8a217.png)
![](https://img.xkw.com/dksih/QBM/2022/12/17/3132770173321216/3141202387443712/STEM/f234c04730d34c219cc65a9b16e57a5d.png?resizew=192)
A.①→③→②→④ | B.①→③→④→② | C.②→③→①→④ | D.②→③→④→① |
您最近一年使用:0次
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9卷引用:河北省廊坊市安次区2021-2022学年八年级下学期期末数学试题
河北省廊坊市安次区2021-2022学年八年级下学期期末数学试题广西壮族自治区百强名校 南宁市第二中学2022-2023学年九年级上学期第三次月考数学试题(已下线)专题18.6 平行四边形的判定(基础篇)(专项练习)-2022-2023学年八年级数学下册基础知识专项讲练(人教版)(已下线)专题9.29 中心对称图形——平行四边形(全章复习与巩固)(基础篇)(专项练习)-2022-2023学年八年级数学下册基础知识专项讲练(苏科版)(已下线)专题4.12 平行四边形的判定定理(基础篇)(专项练习)-2022-2023学年八年级数学下册基础知识专项讲练(浙教版)(已下线)专题4.5 三角形的中位线-【帮课堂】2022-2023学年八年级数学下册同步精品讲义(浙教版)(已下线)专题19.9 平行四边形的判定(基础篇)(专项练习)-2022-2023学年八年级数学下册基础知识专项讲练(沪科版)(已下线)黄金卷05-【赢在中考·黄金8卷】备战2023年中考数学全真模拟卷(河北专用)(已下线)专题6.6 平行四边形的判定(基础篇)(专项练习)-2022-2023学年八年级数学下册基础知识专项讲练(北师大版)
名校
3 . 我们知道,三角形的中位线平行于三角形的第三边,并且等于第三边的一半,如何证明三角形中位线定理呢?
(1)【方法回顾】证明:三角形中位线定理.
已知:如图,在
中,
、
分别是
、
的中点.
求证:
,
.
证明三角形中位线性质定理的方法很多,但多数都需要通过添加辅助线构图去完成,下面是其中一种证法的添加辅助线方法,阅读并完成填空:
添加辅助线,如图1,在
中,过点
作
,与
的延长线交于点
.可证
______,根据全等三角形对应边相等可得
,然后判断出四边形
是______,根据图形性质可证得
,
.
(2)【方法迁移】如图2,在四边形
中,
,
,
,
为
的中点,
、
分别为
、
边上的点,若
,
,
,求
的长.
(3)【定理应用】如图3,在
中,
,
是
的中点,
是边
上一点,
,延长
至点
,使
,延长
交
于点
,直接写出
的值(用含
的式子表示).
(1)【方法回顾】证明:三角形中位线定理.
已知:如图,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c436f108fd4921dae15ecff19270237e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/950e82a0f9712457f2dd9f8a93f8a217.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/7/83dd4fe3-36f7-4435-9765-7319b99cff7d.png?resizew=150)
证明三角形中位线性质定理的方法很多,但多数都需要通过添加辅助线构图去完成,下面是其中一种证法的添加辅助线方法,阅读并完成填空:
添加辅助线,如图1,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe9f641563e8533a5bb39188aa7cc182.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa2f359d983ea52797dfc76023366a8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fe6d389a6c448d92b79d89bc9e8489f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/211c130e20ea36d96e88927f88df956e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c436f108fd4921dae15ecff19270237e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/950e82a0f9712457f2dd9f8a93f8a217.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/7/bdbe31a0-2ab3-4ab0-9199-3a509282c045.png?resizew=192)
(2)【方法迁移】如图2,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f89deb952f57f4b3fa4887b098b7b91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b0ce914a50f5376766d5065e5f13d96.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.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/bae2736ade41af30db54753220a71eaf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/169145cfb31e4fc502a3b2f47a644831.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5eba8bf0c4a8e49b3fac25832a0b0005.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0e57a13c665af88f326c9890072bf73.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/7/5e5c7daa-f6f8-40bc-81bd-7ff4cdc2546b.png?resizew=148)
(3)【定理应用】如图3,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71c472fb321d44281f1e6c4da4ecff6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9d972436cf9555f63b7164b6f7feaa9.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/0ce6e0c28898e278d164e846536b85f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/899f4daf6f7a4d61c16c0f5214461dee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf3834d7ec7531f3c3c0ce9b286f7a49.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/7/61f1766e-d8be-456a-acfc-fad9a18f800d.png?resizew=142)
您最近一年使用:0次
2023-05-21更新
|
324次组卷
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3卷引用:2023年江苏淮安市中考二模数学试题
4 . 如图,四边形
是平行四边形,
,
,点
是
的中点,点
是
延长线上一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/15/95b581eb-8cea-4ee6-b212-aec2bfe5d2d6.png?resizew=150)
(1)连接
,求证:
.
(2)若
.求证:
.
(3)在(2)的条件下,若
的延长线与
交于点
,试判断四边形
是否为平行四边形
并证明你的结论(请补全图形,再解答)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fc13fe21e64d9b45614ed43be847904.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35333abd7f02d663d15251bc5cbbf921.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/15/95b581eb-8cea-4ee6-b212-aec2bfe5d2d6.png?resizew=150)
(1)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de2c0c8cf35a26a344e9bd19350ee77d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65e1e2732f6ae805698f94cc65f14d98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2a3f5d73bae2ab3a31c353d38382d25.png)
(3)在(2)的条件下,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2319a01218514917e446dfc807a625ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82d4c92b24cb675c2aa0d0f80abc59e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
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5 . 如图,
是
的中线,点
是
上一点,过点
作
的平行线,过点
作
的平行线,两平行线交于点
,连接
,
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/16/a10d6927-c709-4c3d-8c56-7e4979ac1bfa.png?resizew=496)
【方法感知】如图①,当点
与点
重合时,易证:
.(不需证明)
【探究证明】如图②,当点
与点
不重合时,求证:四边形
是平行四边形.
小新同学受到【方法感知】中的启发,经过思考后延长
交
于点
.
请完成小新同学的证明过程.
【结论应用】如图③,当
,
时,
的延长线交
于点
,且点
为
中点.
(1)
= .
(2)当
时,
的长为 .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.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/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/16/a10d6927-c709-4c3d-8c56-7e4979ac1bfa.png?resizew=496)
【方法感知】如图①,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f04006562d5654e3daa4be3422aa454e.png)
【探究证明】如图②,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd4b93d7abcfc4c3df48f03aa969c17f.png)
小新同学受到【方法感知】中的启发,经过思考后延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
请完成小新同学的证明过程.
【结论应用】如图③,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f12cacb8b66100d800356b2ba0b0df6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fb01d2b57580731c8b807ac8cffc8ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bca99b3593258bd2b6921a206757d582.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
您最近一年使用:0次
6 . 【回归课本】我们曾学习过一个基本事实:两条直线被一组平行线所截,所得 的对应线段成比例.
【初步体验】
(1)如图 1,在
中,点 D 在
上,E 在
上,
.若
,
,则
,
;
(2 ) 已知,如图 1 ,在
中,点 D 、E 分别在
、
上,且
. 求证:
.
证明:过点
作
的平行线交
于点 F
… … … … … …
请依据相似三角形的定义(如果两个三角形各角分别相等,且各边对应成比例,那么这两个三角形相似)和上面的基本事实 ,补充上面的证明过程;
【深入探究】
(3 )如图 2,如果一条直线与
的三边
、
、
或其延长线交于 D、F、E 点,那么
是否为定值?若是,试求出该定值;若不是,请说明理由;
(4) 如图 3 ,在
中,D 为
的中点,
.则
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/14/ae81c531-d5ee-4ccb-9391-7ce927ac765a.png?resizew=529)
【初步体验】
(1)如图 1,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/1d021981c03e75b1a246d899dcc64656.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df3dc758cc1d4d51bb6ce6f47bd5c0c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6aa482e833f2776208cd17898df8a00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e7a5de06d5577a27967d000e360e851.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b385329fa0199e30da2ccfdf559ebf70.png)
(2 ) 已知,如图 1 ,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb49a110acec1e86b8e8969300f0cd2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d021981c03e75b1a246d899dcc64656.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf7846ba012ffe408dab3eea7f83688d.png)
证明:过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
… … … … … …
请依据相似三角形的定义(如果两个三角形各角分别相等,且各边对应成比例,那么这两个三角形相似)和上面的
【深入探究】
(3 )如图 2,如果一条直线与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb49a110acec1e86b8e8969300f0cd2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9c68b7cf8784793f242f78c3b74914c.png)
(4) 如图 3 ,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7b777bade319d8945e7c8af5a348abd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd7432d82861776bb376477d0894bb55.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/14/6ea62ff8-654e-47fe-b134-21cc5d805f96.png?resizew=587)
您最近一年使用:0次
7 . 如图,在
中,
,
、
、
分别是
、
、
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/1/e25be86b-7291-4425-bcdb-93d6ac8a4bab.png?resizew=118)
(1)求证:
.
(2)连接
、
,求证:四边形
为矩形.
(3)
满足什么条件时,四边形
为正方形,并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/1/e25be86b-7291-4425-bcdb-93d6ac8a4bab.png?resizew=118)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf857e03d4320c999d328fd657c2d412.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
您最近一年使用:0次
8 . 回归课本,完成证明
三角形中位线定理:三角形的中位线平行于第三边且等于第三边的一半.
已知:如图,在
中,点D、E分别是
、
边的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/28/9938a2e1-a4f4-4921-aaf1-7d8917eac352.png?resizew=202)
(1)求证:______________
(2)证明:延长
至点F,使得
,连接
.
三角形中位线定理:三角形的中位线平行于第三边且等于第三边的一半.
已知:如图,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/28/9938a2e1-a4f4-4921-aaf1-7d8917eac352.png?resizew=202)
(1)求证:______________
(2)证明:延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9a9618018d717926540d1452f76e44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
您最近一年使用:0次
名校
9 . 如图,在
中,
,
是
的中位线,
是
的中线.求证
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/26/cbdc617f-26f8-496c-855f-2735d0b37fab.png?resizew=229)
(1)小明给出了如下证明过程,请把小明的证明过程补充完整;
证明:
是
的中位线,
__________.
是
的中线,
,
__________.
.
(2)请你用和小明不同的方法证明
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74e46fb91464159b80eab7c28a926b4e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/26/cbdc617f-26f8-496c-855f-2735d0b37fab.png?resizew=229)
(1)小明给出了如下证明过程,请把小明的证明过程补充完整;
证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1949518fc246fbd8426d08f701ade25d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ae68aba89ee15a23b86e2d13beaa638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b59803eeafe00a6247dbe431ab6c1c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edfe28ce80b846c815003ca883e04739.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/feca660cc9777812ea3cf2e4d21f17b1.png)
(2)请你用和小明不同的方法证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74e46fb91464159b80eab7c28a926b4e.png)
您最近一年使用:0次
2023-04-21更新
|
163次组卷
|
10卷引用:江苏省南京市栖霞区2019-2020学年八年级下学期期中数学试题
江苏省南京市栖霞区2019-2020学年八年级下学期期中数学试题江苏省南京市联合体2019-2020学年八年级下学期期中数学试题河南省长葛市2019-2020学年八年级下学期期末数学试题湖北省襄阳市襄城区2019-2020学年八年级下学期期末数学试题江苏省扬州市仪征市2021-2022学年八年级下学期期中数学试题江苏省南京市秦淮区2022-2023学年八年级下学期期中数学试题江苏省宿迁市泗洪县2022-2023学年八年级下学期期中数学试题(已下线)专题18.11 矩形(知识梳理与考点分类讲解)-2023-2024学年八年级数学下册基础知识专项突破讲与练(人教版)江苏省苏州市高新区实验初级中学2023-2024学年八年级下学期第一次月考数学试题江苏省苏州市苏州高新区实验初级中学2023-2024学年八年级下学期3月月考数学试题
10 . 如图,
于点
于点
,连接
分别为
的中点,连接
.
(1)求证:
.
(2)猜想线段
之间的数量关系并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8915e8e775538d41debf1933102c6b86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fa620049b35962c823b26debcbaa33b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4434bfbff8d44b3f0b96046232f01654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6c8b21a087818284c9cd909cc56c814.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/8/236b4b33-19b5-44d9-a14e-a906faaa2694.png?resizew=236)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/333ab24c4935210f4c232cd0c0fae358.png)
(2)猜想线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c30ac5adb0b9c4419d61b68b72dbd8d.png)
您最近一年使用:0次