【问题提出】(1)如图1,在四边形
中,
,
,
,连接
.试探究
、
、
之间的数量关系.
小明的思路是:他发现
和
互补,推得
,于是想到延长
到点
,使
,连接
.从而得到
,然后证明
,不难得到
、
、
之间的数量关系是______;
【问题变式】(2)如图2,四边形
中,
,
,连接
,试探究
、
、
之间的数量关系,并说明理由;
【问题拓展】(3)如图3,四边形
中,
,
,
,连接
,若
,求四边形
的面积.(直接写出结果)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b0382c28547d3834ca71f3f0677695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
小明的思路是:他发现
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bd602a957d7f6d0940f79a1121b78c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4388f8dbb718da77cd86245dd3a1854.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ffae22f161495ba3552ee0c1caf53ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/794864fd80e17926f60405538153b37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
【问题变式】(2)如图2,四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23b6e08fde74010412a6f14ad4dfbcc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
【问题拓展】(3)如图3,四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eee296a7d9fba487f1485c61580196f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00ec435aa1401dbce7863b531bf2f3e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e1f4f255d191786f7d330d278868c2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
23-24八年级下·湖北咸宁·期中 查看更多[2]
更新时间:2024-05-15 20:43:34
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图,梯形
中,
,点F在
上,连
与
的延长线交于点G.
(1)求证:
;
(2)当点F是BC的中点时,过F作
交
于点E,若
,
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0fff774b4b0087a6f304ce930d359be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/3/27d9017d-be09-4954-aed0-967c08eb7bd2.png?resizew=170)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/219f927a9e0c4faab23c1f3a8a355209.png)
(2)当点F是BC的中点时,过F作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/117878cbd8c00f2aabcdf62b487e2dc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6747441b260ca043446b5d472fece440.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9ff550b6ec45ceadaf479b9c8923e7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
您最近一年使用:0次
【推荐2】【阅读理解】
课外兴趣小组活动时,老师提出了如下问题:
![](https://img.xkw.com/dksih/QBM/2022/11/10/3106567286128640/3107633378607104/STEM/ebb8f66a03194029b6395f8393f87e24.png?resizew=295)
如图1,
中,若
,求
边上的中线
的取值范围.
小明在组内经过合作交流,得到了如下的解决方法:如图2,延长
到点E,使
,连接
.请根据小明的方法思考:
(1)如图2,由已知和作图能得到
的理由是 .
A.SSS B.SAS C.AAS D.ASA
(2)如图2,
长的取值范围是 .
A.
B.
C.
D.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/142869a7cc5e90b551b38210deff9f0f.png)
【感悟】
解题时,条件中若出现“中点”、“中线”字样,可以考虑延长中线构造全等三角形,把分散的已知条件和所求证的结论转化到同一个三角形中.
【问题解决】
(3)如图3,
是
的中线,
交
于点E,交
于F,且
.求证:
.
课外兴趣小组活动时,老师提出了如下问题:
![](https://img.xkw.com/dksih/QBM/2022/11/10/3106567286128640/3107633378607104/STEM/ebb8f66a03194029b6395f8393f87e24.png?resizew=295)
如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04952752bd4ae5692e2b3199cb79d99f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
小明在组内经过合作交流,得到了如下的解决方法:如图2,延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ad98ad714864041a632ca949308e417.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
(1)如图2,由已知和作图能得到
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82e101f2ad5cbdb169f866f0ea82f897.png)
A.SSS B.SAS C.AAS D.ASA
(2)如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
A.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f863e3893cda99d0a42b469f9b0438cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e145a085312b8fa4af76b85fd7669413.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab7f502effec463bec4889245c4f09a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/142869a7cc5e90b551b38210deff9f0f.png)
【感悟】
解题时,条件中若出现“中点”、“中线”字样,可以考虑延长中线构造全等三角形,把分散的已知条件和所求证的结论转化到同一个三角形中.
【问题解决】
(3)如图3,
![](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/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3767efa8adfb71001ad39df9560cbf6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5787c784b686435a2073bdeb836307c.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,△ABC中,AB=AC,∠BAC=120°,AD⊥AC交BC于点D,求证:CD=2AD.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/6/3e652a6f-1db0-43c9-8b25-b2b3741a2467.png?resizew=183)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,等边
的边长为12,
为
边上一动点,过
作
于点
,过点
作
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/6/8602c155-7ffe-467f-b1b2-6a946bb91927.png?resizew=117)
(1)若
,求
的长;
(2)
取何值时,
.
![](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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bffd657e48b15b9b54a55817e2c26b22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8de4a54cc7818be87a239f6de5f5d05b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/6/8602c155-7ffe-467f-b1b2-6a946bb91927.png?resizew=117)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f805768a5ffaf8bdfa4bc3b680aafdc9.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在
中,
,
,将
绕点
逆时针旋转
得到
,连接
,
![](https://img.xkw.com/dksih/QBM/2020/12/19/2617411428048896/2684044744187904/STEM/8a9b4477-ce5b-46ff-99b4-7fa05c8316dc.png)
(1)
,连接
,则
的长是 .
(2)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/901c9e0d6c246c195b65100f3f622899.png)
(3)连接
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfa8cee7d2463f6f7d352e8b65f47cf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb4957406b21df59fdf7fa184752287b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48824e6d1613d4b1b9b28401f2b5a0b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://img.xkw.com/dksih/QBM/2020/12/19/2617411428048896/2684044744187904/STEM/8a9b4477-ce5b-46ff-99b4-7fa05c8316dc.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4cc597393e0d908239503715fd65840.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7785afeeaf274892253d04b4f693b367.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7785afeeaf274892253d04b4f693b367.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/901c9e0d6c246c195b65100f3f622899.png)
(3)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图,四边形ABCD中,AD∥BC,AB⊥BC,△ BDC为等边三角形,点E,F分别为BD,CD的中点.
![](https://img.xkw.com/dksih/QBM/2022/1/24/2901479597686784/2901544435990528/STEM/d64722594bdc42bebeb8f49019d43ed1.png?resizew=204)
(1)求证:四边形AEFD是菱形;
(2)若BC=2,求四边形ABCD的面积.
![](https://img.xkw.com/dksih/QBM/2022/1/24/2901479597686784/2901544435990528/STEM/d64722594bdc42bebeb8f49019d43ed1.png?resizew=204)
(1)求证:四边形AEFD是菱形;
(2)若BC=2,求四边形ABCD的面积.
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,在
中,
,
垂直平分
,分别交线段
于点D、E,连接
,若
,
.
的长度;
(2)延长线段
使得
,连接
,求四边形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/887721a843b2dc8e947cc42d09868e33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6b0a3fa475b24f57ecd79c681259561.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4107f9817489bd8938b16076df1469a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86338536656046e93b53672ade9a78b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(2)延长线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dacca19f76d406c300d549a5a35ce6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f92d3a98b016927de4bbb9b9564894f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d36c37267c4aeecee473d19457f585.png)
您最近一年使用:0次