名校
1 . 如图,在
中,点
,
分别在
,
上,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92034dd2bb9480b18709d01153467f8f.png)
是平行四边形;
(2)若
,
,请判断四边形
为哪类特殊的平行四边形,并加以证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5138a9f70d5e8b0580e30fef6eb7baef.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92034dd2bb9480b18709d01153467f8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/822ba132ca9dd0d4a050659aef3c9b26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/138c0d201baff3e0f7b9de6544317fbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
您最近一年使用:0次
名校
2 . 如图,在平行四边形
中,点
、
、
、
分别在边
、
、
、
上,
,
.
是平行四边形;
(2)当
,且
时,请判断四边形
的形状并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f96461af9193d5d7867ddf8fcbefcaec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b9d7b4c41c5815fac4e1786f77c0596.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0f90a3773e6944013a0eb41279f332f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c89029e1d782dbf6a0bda8605a7c5ad4.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c029f2663b3fd557c9169e295c353e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7c390d67e0d91ae3ad99cf6a9d173f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c89029e1d782dbf6a0bda8605a7c5ad4.png)
您最近一年使用:0次
3 . 命题:在同一平面内,垂直于同一直线的两条直线互相平行,画出图形,写出该命题的已知、求证,并证明.
您最近一年使用:0次
4 . 完成下面的证明过程.
已知:如图,
,求证:
平分
.
(已知),
( ),
( ),
又
(已知),
( ),
平分
( )
已知:如图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bae4dfa9539ea5d1b9957f6f52a8f9a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35803969509655f72b4118503ae1c966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb6706c88443ead35c76bcf2f3ec24aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78163b1e78c917f86dc961a038329ff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/064c359bafcd1841d582707419d1ac2d.png)
又
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df7a0621aafbc7e55cd6f6b9686c214b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cb74854a2ddf9c137853bd6476af609.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3e24c2bdad41127f07c6639a357d2b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35803969509655f72b4118503ae1c966.png)
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5 . (1)如图①,
和
为等腰直角三角形,
,求证:
.
(2)如图②,
,
,试探究线段
与线段
的关系,并加以证明.
(3)如图③,
,
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90b40c2b0ab8e1cfe5112d428b4b829f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a0acc93490a6a784eb62201d93dd93d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fc75953bf5dcfa4af308c34bf9952d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eac6f98ed81727dc5f6699ea5117fff.png)
(2)如图②,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fc75953bf5dcfa4af308c34bf9952d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb018be331b3bd70b0ad11e0bd9f12be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
(3)如图③,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8501c6b8c3ea9a9b965504ab987626b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9fbdef9d23784b3d2c6dda57634e442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
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6 . 如图,在四边形
中,
,
.
上截取
,连接
,作
的角平分线
,分别交
于点F、G,连接
.(保留作图痕迹,不写作法)
(2)在(1)所作图形中,求证:
.(请补全下面的证明过程,不写证明理由)
证明:∵
是
的角平分线,
∴ ,
∵
,
∴ ,
∴
,
∴ ,
又∵
,
∴ ,
∴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/6dceb5cc71fc50f20649f6b9535fd914.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a626eb07074f222d52c129b275e173d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be5fc6ead6416492c231c320a5486f86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a7e4a6765ce78b05ee97764771e01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ab6fb62038b9207669ce6f8309fb142.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e55e398e8520d8a36fb5a625a085b8.png)
(2)在(1)所作图形中,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d440215e4ca391884e61b1017e329e4.png)
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a7e4a6765ce78b05ee97764771e01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
∴ ,
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dceb5cc71fc50f20649f6b9535fd914.png)
∴ ,
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2a40e29b48b7a23bc25eb615bbe5f5d.png)
∴ ,
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be5fc6ead6416492c231c320a5486f86.png)
∴ ,
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7419886f571571b57b61a6a8980305e8.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d440215e4ca391884e61b1017e329e4.png)
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7 . 如图,四边形
是矩形,连接
交于点
平分
交
于点
.
的角平分线交
于点
,连接
;(保留作图痕迹,不写作法与结论)
(2)求证:四边形
是平行四边形.
证明:∵四边形
是矩形,
∴
,
∴ ① ,
∵
平分
平分
,
∴
,
∴ ② .
∵在
和
中,
,
∴
,
∴ ④ ,
又∵
,
∴四边形
是平行四边形( ⑤ ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d0b0b7d07ac1aebab6b6f1e8c6acdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a635d7620abb851e2131c63668396e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a457b899731577bfe61dda594ae4eec4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdb8eca20ce2c918ea4034ea15210c7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/269285cf47de45209780078b523ebf46.png)
(2)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
证明:∵四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ff045361a1774085165769608ec4401.png)
∴ ① ,
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fa6f95394a0d93e62ed95035253799d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d3f9b99890e5650853f830170dccea6.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f12a744bfd62512d7b186a5fc09a088.png)
∴ ② .
∵在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea46133f0ce8a230e503f150955c6d6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/684f55970df210065eaa81b898bfdb9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c74792ff1e3ffcacc916a7f1f0228647.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce68b67af24054b057157759cf5417c1.png)
∴ ④ ,
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0944865f14b13a772526c4cae4f29c99.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
您最近一年使用:0次
8 . 【综合与实践】
【探究】(1)小学我们就学过同底等高的两个三角形的面积相等,后来我们又学到等高的两个三角形的面积之比等于与高对应的底边长之比,如图(1),
的高
和
的高
相等,则
同样,同底的两个三角形,如果面积相等,也有类似的结论,若图形位置特殊,由此会产生一些新的结论,下面是小江同学探索的一个结论,请帮助小江完成证明.
和
的面积相等,求证:
.
证明:分别过点
、点
作
和
底边
上的高线
,
.
【应用】(2)把图(3)的四边形
改成一个以
为一边的三角形,并保持面积不变,请画出图形,并简要说明理由.
【拓展】(3)用上述探究的结论和已经证明的结论,证明三角形的中位线定理.
已知:如图(4),______.
求证:______.
证明:
【探究】(1)小学我们就学过同底等高的两个三角形的面积相等,后来我们又学到等高的两个三角形的面积之比等于与高对应的底边长之比,如图(1),
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36e5e61804ce550636a0354e0a78a22d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/301941880d65680d8133f05b2785ce64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41f0dadf037efedc90b39c57a6880a1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
证明:分别过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41f0dadf037efedc90b39c57a6880a1a.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/d004d2d115b477ade6af7ddb93db0df8.png)
【应用】(2)把图(3)的四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
【拓展】(3)用上述探究的结论和已经证明的结论,证明三角形的中位线定理.
已知:如图(4),______.
求证:______.
证明:
您最近一年使用:0次
2024-06-17更新
|
119次组卷
|
2卷引用:2024年浙江省杭州市滨江区九年级中考数学一模试题
9 . 请把下面证明过程补充完整.
,
,
.
求证:
.
证明:∵
,
(______________),
∴
(______________).
∴________
________(__________________________________).
∴
(______________________________).
又∵
(已知),
∴____________(等量代换).
∴
(________________________________).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc90fee532e50d319081d571410421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0d2b4784ca73e0478d3ae08fd494a8f.png)
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc90fee532e50d319081d571410421.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c613c8ea8b1abe76b803ae12316a8f9.png)
∴________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16acdcaac54dcfe8cc11accda9363987.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
∴____________(等量代换).
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0d2b4784ca73e0478d3ae08fd494a8f.png)
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10 . 请把下面证明过程补充完整:
已知:如图,
,
分别平分
,且
.
求证:
.
分别平分
(已知),
,
( ).
(已知),
(等量代换),
(已知),
(等量代换).
∴
( ).
,
( ).
( ).
已知:如图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97e3555cd6c109962fecba3a677c5286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca7b50da9fef51f37b4813746d77a33a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a3f0bff977fd039f3fc3eb948872015.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1393308bc68322f50fa29702dd412263.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f421d57aeeab4b5cc3dfef87fa2741c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a3f0bff977fd039f3fc3eb948872015.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0332b8ee40be451e9affe3fc05416a6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/897e4b62b32f65075dc17081bacc226d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e3566b290df69bb5f10831037baf77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/758dc5363d5b601cd457da948795f951.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c08980b6afedc04aa04f385791f0163.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d98228bd5ecb89ef69c62a71f8e1ae6.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b10ed511b90550169c0915873074d3a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53e519cdb0cac3981d8e9610dba507a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b69cb1f880adf75d2290d599e858463.png)
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