真题
名校
1 . 【性质探究】
如图,在矩形ABCD中,对角线AC,BD相交于点O,AE平分∠BAC,交BC于点E.作DF⊥AE于点H,分别交AB,AC于点F,G.
(1)判断△AFG的形状并说明理由.
(2)求证:BF=2OG.
【迁移应用】
(3)记△DGO的面积为S1,△DBF的面积为S2,当
时,求
的值.
【拓展延伸】
(4)若DF交射线AB于点F,【性质探究】中的其余条件不变,连结EF,当△BEF的面积为矩形ABCD面积的
时,请直接写出tan∠BAE的值.
如图,在矩形ABCD中,对角线AC,BD相交于点O,AE平分∠BAC,交BC于点E.作DF⊥AE于点H,分别交AB,AC于点F,G.
(1)判断△AFG的形状并说明理由.
(2)求证:BF=2OG.
【迁移应用】
(3)记△DGO的面积为S1,△DBF的面积为S2,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dd99004666e1ea4b4d95b30e62254c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fae8822248f489e8fbbf4cc72536a16a.png)
【拓展延伸】
(4)若DF交射线AB于点F,【性质探究】中的其余条件不变,连结EF,当△BEF的面积为矩形ABCD面积的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5723639e0b63d91f0cae56954620b726.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/12/7c072ff7-c00f-411a-8106-f69fd45733c1.png?resizew=169)
您最近一年使用:0次
2020-07-03更新
|
2211次组卷
|
6卷引用:浙江省衢州市2020年中考数学试题
浙江省衢州市2020年中考数学试题(已下线)浙江省衢州市2020年中考数学试题(已下线)重难点06 几何类综合问题-2021年中考数学【热点·重点·难点】专练(已下线)专题16 相似三角形与位似图形-三年(2020-2022)中考数学真题分项汇编(浙江专用)浙江省金华市义乌市绣湖中学2022-2023学年九年级上学期12月月考数学试题江苏省连云港市灌云县下车中学2022-2023学年九年级下学期9月月考数学试题
2 . 问题发现:(1)如图1,
与
同为等边三角形,连接
则
与
的数量关系为________;直线
与
所夹的锐角为_________;
类比探究:(2)
与
同为等腰直角三角形,其他条件同(1),请问(1)中的结论还成立吗?请说明理由;
拓展延伸:(3)
中
,
为
的中位线,将
绕点
逆时针自由旋转,已知
,在自由旋转过程中,当
在一条直线上时,请直接写出
的值.
![](https://img.xkw.com/dksih/QBM/2020/7/2/2497043290292224/2497327257837568/STEM/5c10ba7a34bd4970942debed8b625184.png?resizew=216)
![](https://img.xkw.com/dksih/QBM/2020/7/2/2497043290292224/2497327257837568/STEM/6fb7ab3f37dc403fb87994036fb7c218.png?resizew=216)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a0acc93490a6a784eb62201d93dd93d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06e8d80f6159c7b21b9238a0696a0da4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
类比探究:(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/890306fa0f59d7192c341794d1342293.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a0acc93490a6a784eb62201d93dd93d.png)
拓展延伸:(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/387649e90d977c66595c127436f10134.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92d38160532e95012fdfbc2a1be264b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/2020/7/2/2497043290292224/2497327257837568/STEM/5c10ba7a34bd4970942debed8b625184.png?resizew=216)
![](https://img.xkw.com/dksih/QBM/2020/7/2/2497043290292224/2497327257837568/STEM/6fb7ab3f37dc403fb87994036fb7c218.png?resizew=216)
![](https://img.xkw.com/dksih/QBM/2020/7/2/2497043290292224/2497327257837568/STEM/38ea4bc750474a0a8c55d19f6a044c56.png?resizew=273)
您最近一年使用:0次
19-20九年级下·江西·期末
解题方法
3 . 定义:有一个角重合,且角的两边叠合在一起的两个相似四边形叫做“嵌套四边形”;如下图中的四边形
和
都是“嵌套四边形”.
【问题猜想】
![](https://img.xkw.com/dksih/QBM/2020/10/29/2581315812311040/2581403759247360/STEM/331319bb-3d13-4305-b8ec-a3063f5c81d1.png)
(1)如图1,嵌套四边形
和
都是正方形,现把正方形
绕点A顺时针旋转
得到正方形
,连接
、
交于点O,则
与
的数量关系是______,位置关系是_____;
【类比探究】
(2)如图2,将(1)中的嵌套四边形
和
换成菱形,
,其它条件不变,则(1)中的结论还成立吗?若成立,请说明理由;若不成立,请给出正确的结论,并说明理由;
【拓展延伸】
(3)如图3,将(1)中的嵌套四边形
和
换成长和宽之比为
的矩形,旋转角换成
,其它条件不变,求出
与
的数量关系和位置关系.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e6f84f2a5721303019f158d860cd5b.png)
【问题猜想】
![](https://img.xkw.com/dksih/QBM/2020/10/29/2581315812311040/2581403759247360/STEM/331319bb-3d13-4305-b8ec-a3063f5c81d1.png)
(1)如图1,嵌套四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e6f84f2a5721303019f158d860cd5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e6f84f2a5721303019f158d860cd5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a12c461765806bbfb872e7e8aa410c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aee1436c64a665449b903a99d7207f50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19324d9bb7f74e7d7bda648642a7fc5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b865d36e3fdd5e443817456469ecda73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19324d9bb7f74e7d7bda648642a7fc5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b865d36e3fdd5e443817456469ecda73.png)
【类比探究】
(2)如图2,将(1)中的嵌套四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e6f84f2a5721303019f158d860cd5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/916f7d1cb36721705840df0644383664.png)
【拓展延伸】
(3)如图3,将(1)中的嵌套四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e6f84f2a5721303019f158d860cd5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbe103f073845122c66f22dcb14b711f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b113dcbe1a087d7a2a356fbee4e8ae5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19324d9bb7f74e7d7bda648642a7fc5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b865d36e3fdd5e443817456469ecda73.png)
您最近一年使用:0次
4 . 综合与实践—四边形旋转中的数学
“智慧”数学小组在课外数学活动中研究了一个问题,请帮他们解答.
问题情境:如图1,在矩形
中,
,
,E,F分别为
,
边的中点,四边形
为矩形,连接
.
![](https://img.xkw.com/dksih/QBM/2020/12/29/2624490989707264/2626112865165312/STEM/c7a77690-d094-4baa-8d87-0b47900468be.png?resizew=543)
特例分析:(1)请直接写出
的长是________.
(2)如图2,当矩形
绕点A旋转(比如顺时针旋转)至点G落在边
上时,请计算
与
的长,通过计算,试猜想
与
之间的数量关系.
深入探究:(3)请从下面A、B两题中任选一题作答.我选择________题
A.当矩形
绕点A旋转至如图3的位置时,(2)中
与
之间的数量关系是否还成立?请说明理由.
B.“智慧”数学小组对图形的旋转进行了拓展研究,如图4,在
中,
,
,
,E,F分别为
,
边的中点,四边形
为平行四边形,连接
.“智慧”数学小组发现
与
仍然存在着特定的数量关系.如图5,当
绕点A旋转(比如顺时针旋转),其他条件不变时,
与
是否还存在着第(2)问中特定的数量关系?请说明理由.
“智慧”数学小组在课外数学活动中研究了一个问题,请帮他们解答.
问题情境:如图1,在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81c91c961e70e3a97c51597bd87e04fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f83df2a880bdd449e0714dc8f23c182c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72794bd3cbe1a898e2254c3dd98a437e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://img.xkw.com/dksih/QBM/2020/12/29/2624490989707264/2626112865165312/STEM/c7a77690-d094-4baa-8d87-0b47900468be.png?resizew=543)
特例分析:(1)请直接写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
(2)如图2,当矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72794bd3cbe1a898e2254c3dd98a437e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
深入探究:(3)请从下面A、B两题中任选一题作答.我选择________题
A.当矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72794bd3cbe1a898e2254c3dd98a437e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
B.“智慧”数学小组对图形的旋转进行了拓展研究,如图4,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5138a9f70d5e8b0580e30fef6eb7baef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3f3258ae37406bbb0520245fa98529f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81c91c961e70e3a97c51597bd87e04fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f83df2a880bdd449e0714dc8f23c182c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72794bd3cbe1a898e2254c3dd98a437e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eb5d7051027fa38366a459c2922392f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
您最近一年使用:0次
5 . 下图是华师版九年级上册数学教材第63页的部分内容.
(1)【教材呈现】
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/3/6e32065a-3ed1-4cd0-892e-24eb1ae4069c.png?resizew=506)
根据教材内容,结合图①,给出例1的完整计算过程.
(2)【感知探究】如图②,
是△
的中线,连结
并延长,交
于点
,
=
,若
=2,则
= .
(3)【应用拓展】如图③,在△
中,点
为边
上的一点,且
=
,在射线
上取一点
,使
=
,连结
并延长交射线
于点
,若
.请直接写出四边形
的面积.
(1)【教材呈现】
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/3/6e32065a-3ed1-4cd0-892e-24eb1ae4069c.png?resizew=506)
根据教材内容,结合图①,给出例1的完整计算过程.
(2)【感知探究】如图②,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.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/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb8f67bdef208fc8fbeb35e19bebb13f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
(3)【应用拓展】如图③,在△
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b840be5852709e18ea985954545e78d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3533837e3d08c461dea031a44e5424d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8385faa3c5c3b2bbd7b0752f6f644a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/471b88327a64083fe10e4668f7f1fd00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abe38c885f29722c433022c4b2ae6211.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/3/0b38cfb9-3554-4b61-8e16-c6e3907aaa44.png?resizew=525)
您最近一年使用:0次
6 . 如图1,在
中,
,
,点
,
分别为边
,
的中点,点
在边
上,且
,点
为
的中点,过点
作
交
于点
,点
为
的中点将
绕点
顺时针旋转,旋转角为
,连接![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67c015d99f2677951bdcd0447240ef93.png)
. ![](https://img.xkw.com/dksih/QBM/2020/10/7/2566067879862272/2567063714906112/STEM/7347ef8d97ee42eabef1f6901891504e.png?resizew=554)
(1)问题发现
当
时,
______;直线
与直线
相交所成的较小夹角的度数为______.
(2)类比探究
当
时,(1)中的结论是否仍然成立?若成立,请仅就图2的情形给出证明;若不成立,请说明理由.
(3)拓展应用.
若
,直线
和直线
交于点
,在旋转的过程中,当点
与点
重合时,请直接写出线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f76899b3a0bfbbdae7cb1148ad4bf018.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5181b97a7e43959b8455680157c3b644.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.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/60ef95894ceebaf236170e8832dcf7e3.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/3f3ba8b214034c287276f4966069d95e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0137c721b8d4ea6dca8b7d9761134726.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a0acc93490a6a784eb62201d93dd93d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67c015d99f2677951bdcd0447240ef93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1460aa3d83df61f6c411b34412135451.png)
![](https://img.xkw.com/dksih/QBM/2020/10/7/2566067879862272/2567063714906112/STEM/7347ef8d97ee42eabef1f6901891504e.png?resizew=554)
(1)问题发现
当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e7e8c4e8015bc1a44a89460e1dc0d63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ceb1d9984a5b6453b21fe1778c2445b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67c015d99f2677951bdcd0447240ef93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1460aa3d83df61f6c411b34412135451.png)
(2)类比探究
当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a1ff061891062dba42947d19281cd4f.png)
(3)拓展应用.
若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67c015d99f2677951bdcd0447240ef93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1460aa3d83df61f6c411b34412135451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1460aa3d83df61f6c411b34412135451.png)
您最近一年使用:0次
7 . (1)如图①,在四边形
中,
,点
在
边上,
,求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ec2ec6cf30c455d67c34e27fe4957c.png)
(2)探究:如图②,在四边形
中,点
在
边上,当
时,求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ec2ec6cf30c455d67c34e27fe4957c.png)
(3)拓展:如图③,在
中,点
是边
的中点,点
分别在边
上,若
,求
的长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71069b7ae2205c2f51022bd67e371772.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ec2ec6cf30c455d67c34e27fe4957c.png)
(2)探究:如图②,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/516bcdc180f55d0c66fe19c0712dcaef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ec2ec6cf30c455d67c34e27fe4957c.png)
(3)拓展:如图③,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34ff9d4fdd0d176042505b7aac016852.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91e1e4115d78e625e9e0f47cdade3286.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dec2ca6438c82b43f746057d8129885.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d24f91e93b8b15e9c0ff4923e5015313.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/14/b2917860-4786-4ff2-bb10-11dd13a843e6.png?resizew=500)
您最近一年使用:0次
2020-11-23更新
|
164次组卷
|
2卷引用:四川博瑞特外国语学校2020-2021学年九年级上学期期中数学试题
8 . 如图1,在
中,
,点
分别是边
的中点,连接
.将
绕点
逆时针方向旋转,记旋转角为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/20/e49c4ed8-a173-47cf-ade4-1ae8dc67eab8.png?resizew=196)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/20/5814ccbb-bd52-4405-922f-d4f6a7fc45ae.png?resizew=191)
(1)问题发现
①当
时,
____________;②当
时,
___________.
(2)拓展探究试判断:当
时,
的大小有无变化?请仅就图2的情形给出证明.
(3)问题解决
绕点
逆时针旋转至
三点在同一条直线上时,直接写出线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f8f88798ec42a58dccd212586382b23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7069998d614205c026f617341aa68777.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3a51949f48ee8cf746851ba779b078e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/887721a843b2dc8e947cc42d09868e33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/20/e49c4ed8-a173-47cf-ade4-1ae8dc67eab8.png?resizew=196)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/20/38138f3f-f251-42bf-8705-0078b0059a9c.png?resizew=193)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/20/5814ccbb-bd52-4405-922f-d4f6a7fc45ae.png?resizew=191)
(1)问题发现
①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1324ff7173a4cfdf94521785f83f2c16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce24b781c66474602b5ba6627241531.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0aea70d7674adbcfb6c150aa014c884.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce24b781c66474602b5ba6627241531.png)
(2)拓展探究试判断:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d1ff4548a51c31a2439567fb8b5f27e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/625000a942ec1b76a1176284be6d6520.png)
(3)问题解决
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00045940432a531a8f07034032d9248d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
您最近一年使用:0次
9 . 某数学活动小组在研究三角形的拓展图形及其性质时,经历了如下过程.
操作发现:
(1)①如图1,B为线段
上一点,分别以
,
为边作正方形
,正方形
,点P为
上一点,且
,连接
,
,那么
与
有什么关系?直接写出答案.
②如图2,B为线段
上一点,分别以
,
为斜边作等腰直角三角形
与等腰直角三角形
,点P为
的中点,连接
,
,那么
与
有什么数量关系?请给予证明.
![](https://img.xkw.com/dksih/QBM/2020/9/4/2542406321905664/2542710919946240/STEM/144f26aa-9e10-454a-a37f-d2f9fc1fb25c.png)
数学思考:
(2)如图3,B为线段
上一点,分别以
,
为斜边作直角三角形
,直角三角形
,且
,点P为
的中点,连接
,
,那么
与
有什么数量关系?
请给予证明
![](https://img.xkw.com/dksih/QBM/2020/9/4/2542406321905664/2542710919946240/STEM/a2110ab1-e55f-44ef-9dcb-04d57cc0332d.png)
拓展探究:
(3)如图4,B为线段
外一点,连接
,
分别
,
为斜边作直角三角形
,直角三角形
,且
,点P为
的中点,连接
,
,那么(2)中的结论还成立吗?若成立,请给予证明;若不成立,请说明理由.
操作发现:
(1)①如图1,B为线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbc7ee0ef8945ba1b90e59aed7cab889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b539ad330f39b9ea2e9ebb3c99a2489.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c2293f93791a597bf0162411f3395f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c2293f93791a597bf0162411f3395f.png)
②如图2,B为线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/152cfd5011c94e02c1a9cbbd4d8f58bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://img.xkw.com/dksih/QBM/2020/9/4/2542406321905664/2542710919946240/STEM/144f26aa-9e10-454a-a37f-d2f9fc1fb25c.png)
数学思考:
(2)如图3,B为线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/152cfd5011c94e02c1a9cbbd4d8f58bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c50524f9df8353f6a81de4f76bb3c4c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
请给予证明
![](https://img.xkw.com/dksih/QBM/2020/9/4/2542406321905664/2542710919946240/STEM/a2110ab1-e55f-44ef-9dcb-04d57cc0332d.png)
拓展探究:
(3)如图4,B为线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/152cfd5011c94e02c1a9cbbd4d8f58bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c50524f9df8353f6a81de4f76bb3c4c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
您最近一年使用:0次
10 . 在△ABC中,AD为BC边上的中线,E为AD上一动点,设DE=nEA,连接CE并延长,交AB于点F.
(1)尝试探究:如图1,当∠BAC=90°,∠B=30°,DE=EA时,BF,BA之间的数量关系是 ;
(2)类比延伸:如图2,当△ABC为锐角三角形,DE=EA时,(1)中的结论是否仍然成立?若成立,请给予证明;若不成立,请说明理由;
(3)拓展迁移:如图3,当△ABC为锐角三角形,DE=nEA时,请直接写出BF,BA之间的数量关系.
(1)尝试探究:如图1,当∠BAC=90°,∠B=30°,DE=EA时,BF,BA之间的数量关系是 ;
(2)类比延伸:如图2,当△ABC为锐角三角形,DE=EA时,(1)中的结论是否仍然成立?若成立,请给予证明;若不成立,请说明理由;
(3)拓展迁移:如图3,当△ABC为锐角三角形,DE=nEA时,请直接写出BF,BA之间的数量关系.
![](https://img.xkw.com/dksih/QBM/2020/5/2/2453824099475456/2454156950659072/STEM/5d81328b8e0c4b1ea9970fdc62510e17.png?resizew=413)
您最近一年使用:0次