如图,在
中,点
,
分别是边
,
的中点,点
,
是边
的三等分点,
,
的延长线相交于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/25/a3c695d8-b769-4c56-afdc-1fae4d27c34a.png?resizew=224)
(1)求证:四边形
是平行四边形.
(2)求证:四边形
是平行四边形.
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e55e398e8520d8a36fb5a625a085b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/25/a3c695d8-b769-4c56-afdc-1fae4d27c34a.png?resizew=224)
(1)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78b07813edf63bca1db33ad6d3a2d69a.png)
(2)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55bf39b6c78f5b45d8e5e908960e2cf5.png)
21-22八年级下·浙江宁波·期末 查看更多[2]
更新时间:2022-09-21 19:42:35
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,四边形ABCD是平行四边形,E,F是对角线BD上的点,
.
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92034dd2bb9480b18709d01153467f8f.png)
(2)线段AF与CE有什么关系?请证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92034dd2bb9480b18709d01153467f8f.png)
(2)线段AF与CE有什么关系?请证明你的结论.
![](https://img.xkw.com/dksih/QBM/2021/6/25/2750564468998144/2768475400019968/STEM/80d368a0-d9fa-4205-a640-6a74be5dd13b.png?resizew=219)
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解答题-作图题
|
适中
(0.65)
名校
【推荐2】【教材呈现】如图是华师版九年级上册第77﹣78页部分内容:
如图1,在△ABC中,点D、E分别是AB与AC的中点,根据画出的图形,可以猜想:DE
BC,且DE=
BC.
结论:三角形的中位线平行于第三边,并且等于第三边的一半.
证明:在△ABC中,
∵点D、E分别是AB与AC的中点,
∴
,
∵∠A=∠A,
∴△ADE
△ABC,
∴∠ADE=∠ABC,
,
∴DE
BC,且DE=
BC.
![](https://img.xkw.com/dksih/QBM/2022/6/11/2999071934595072/3015579478589440/STEM/3525bd7a97ec493f81e97a87160c9cb8.png?resizew=207)
![](https://img.xkw.com/dksih/QBM/2022/6/11/2999071934595072/3015579478589440/STEM/f82c4c830ed64046b41d86952ec2b62e.png?resizew=552)
(1)【探究】如图2,△ABC中,点D、F分别为边AB、AC的中点,点G、E在边BC上.若DG
FE,求证:S四边形DFEG=
S△ABC.
(2)【应用】如图3,△ABC中,点E、F分别为边AB、AC的中点,D在线段AB上(不与点A、B重合),点H、G分别为线段DB、DC的中点,若S△ADC=5,则S四边形EFGH= .
(3)【拓展提升】如图4,在△ABC中,D、E分别在边BA、BC上.
,在线段DE上取一点F,(点F不与点D、E重合),连接BF并延长BF交AC于点G.点M、N在线段AC上,且AM=2EF,CN=2DF,若S△ABC=25,求S△FAM+S△ENC的值.
如图1,在△ABC中,点D、E分别是AB与AC的中点,根据画出的图形,可以猜想:DE
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
结论:三角形的中位线平行于第三边,并且等于第三边的一半.
证明:在△ABC中,
∵点D、E分别是AB与AC的中点,
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd53b96cb75d0f1b948d01b111496d.png)
∵∠A=∠A,
∴△ADE
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3ceeb5e5ad5cd7e520e231d523709ca.png)
∴∠ADE=∠ABC,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58668ac5c3b089ffee1fbaa6fba07df6.png)
∴DE
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://img.xkw.com/dksih/QBM/2022/6/11/2999071934595072/3015579478589440/STEM/3525bd7a97ec493f81e97a87160c9cb8.png?resizew=207)
图1
![](https://img.xkw.com/dksih/QBM/2022/6/11/2999071934595072/3015579478589440/STEM/f82c4c830ed64046b41d86952ec2b62e.png?resizew=552)
图2 图3 图4
(1)【探究】如图2,△ABC中,点D、F分别为边AB、AC的中点,点G、E在边BC上.若DG
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
(2)【应用】如图3,△ABC中,点E、F分别为边AB、AC的中点,D在线段AB上(不与点A、B重合),点H、G分别为线段DB、DC的中点,若S△ADC=5,则S四边形EFGH= .
(3)【拓展提升】如图4,在△ABC中,D、E分别在边BA、BC上.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afb13137b1ad6a10461bbc1d6128f79f.png)
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解答题-证明题
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适中
(0.65)
【推荐1】如图,在△ABC中,BC=AC=6,以BC为直径的⊙O与边AB相交于点D,DE⊥AC,垂足为点E.
(1)求证:点D是AB的中点;
(2)求点O到直线DE的距离.
(1)求证:点D是AB的中点;
(2)求点O到直线DE的距离.
![](https://img.xkw.com/dksih/QBM/2019/1/1/2109366936174592/2110291513466880/STEM/71ba4b8d1d5f46b283cc1ed7a6a74e43.png?resizew=135)
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解答题-计算题
|
适中
(0.65)
【推荐2】(1)计算:
.
(2)如图,在
中,D,E分别是
,
的中点,连接
并延长至点F,延长BC至点G,使得
,连接
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e056e3f333fd88c771edc1ae77262e6e.png)
(2)如图,在
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baedb038db26d9c599cdd2414695d772.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/feb2f646f44a4e93cd5959b598eb57df.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/20/524ccc17-5207-486f-8b4f-779850c7180b.png?resizew=166)
您最近一年使用:0次