如图1,四边形ABCD、CEGF都是矩形,点G在AC上,且
,AB=9,AD=12,小李将矩形CEGF绕点C顺时针转
°(0≤
≤360°),如图2所示
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/13/6dbd84d1-ee65-4ab5-8cbd-23de5455cee8.png?resizew=516)
(1)①他发现
的值始终不变,请你帮他计算出
的值= .
② 在旋转过程中,当点B、E、F在同一条直线上时,求出AG的长度是多少?
(2)如图3,△ABC中,AB=AC=
,∠BAC=
°,tan∠ABC=
,G为BC的中点,点D为平面内的一个动点.且DG=
,将线段BD绕点D逆时针旋转
°,得到D
,则四边形BAC
的面积最大值为 .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74e57df60033d608b88b3f0f5781dbc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2085f3a381a64c3fe3896c64184ea8c8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/13/6dbd84d1-ee65-4ab5-8cbd-23de5455cee8.png?resizew=516)
(1)①他发现
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45ec2c1bca9d89d16df525a45408aa76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45ec2c1bca9d89d16df525a45408aa76.png)
② 在旋转过程中,当点B、E、F在同一条直线上时,求出AG的长度是多少?
(2)如图3,△ABC中,AB=AC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b91d650c2fc1a741fabdb333b09aeb6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3953cec61ac602ce5eb59b7912352179.png)
更新时间:2022-04-23 16:31:40
|
相似题推荐
解答题-证明题
|
困难
(0.15)
【推荐1】综合与实践
综合实践课上,老师让同学们以“三角形纸片的折叠”为主题开展数学活动.
(1)【操作发现】对折![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
,使点
落在边
上的点
处,得到折痕
,把纸片展平,如图1.小明发现四边形
满足:
,
.查阅相关资料得知,像这样的有两组邻边分别相等的四边形叫作“筝形”.请写出图1中筝形
的一条性质:_________.
(2)【拓展探究】如图2,连接
,
、
、
、
分别为
、
、
、
的中点.
①求证:筝形
的面积
;
②若
的面积为64,
的面积为12,求四边形
的面积.
(3)【迁移应用】如图3,在
中,
,
,点
、
分别在
、
上,当四边形
是筝形,
时,直接写出四边形
的面积.
综合实践课上,老师让同学们以“三角形纸片的折叠”为主题开展数学活动.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/6/d55503ac-7b24-4039-ab5c-71c5ac45c253.png?resizew=629)
(1)【操作发现】对折
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3ba09c500dae87c779bc5291eb549d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.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/1f56fe2c1064b804bb235fe72a4af288.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/934a9508c176f44bf58f88715bd98f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3620030e8808da46df97330103827913.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f56fe2c1064b804bb235fe72a4af288.png)
(2)【拓展探究】如图2,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.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/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
①求证:筝形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f56fe2c1064b804bb235fe72a4af288.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/123d394eb9be12b07f78f3af15b81bdb.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07fbad473c16df3ff62c1c6b37de6aa8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da5544d73c25eff276722719c177c54.png)
(3)【迁移应用】如图3,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f89deb952f57f4b3fa4887b098b7b91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d3c9ce32b721995f355eea411340e3.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f56fe2c1064b804bb235fe72a4af288.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/684d2bbdd30443a7b73738d051d9a5dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f56fe2c1064b804bb235fe72a4af288.png)
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解答题-作图题
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困难
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解题方法
【推荐2】阅读理解题.
定义:如果四边形的某条对角线平分一组对角,那么把这条对角线叫做“美妙线”,该四边形叫做“美妙四边形”.
如图,在四边形ABDC中,对角线BC平分∠ACD和∠ABD,那么对角线BC叫“美妙线”,四边形ABDC就称为“美妙四边形”.
问题:
(1)下列四边形:平行四边形、矩形、菱形、正方形,其中是“美妙四边形”的有 个;
(2)四边形ABCD是“美妙四边形”,AB=
∠BAD=60°,∠ABC=90°,求四边形ABCD的面积.(画出图形并写出解答过程)
定义:如果四边形的某条对角线平分一组对角,那么把这条对角线叫做“美妙线”,该四边形叫做“美妙四边形”.
如图,在四边形ABDC中,对角线BC平分∠ACD和∠ABD,那么对角线BC叫“美妙线”,四边形ABDC就称为“美妙四边形”.
问题:
(1)下列四边形:平行四边形、矩形、菱形、正方形,其中是“美妙四边形”的有 个;
(2)四边形ABCD是“美妙四边形”,AB=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12eee1ba0645f99ebe4b0dc0a0441405.png)
![](https://img.xkw.com/dksih/QBM/2020/7/2/2497103254872064/2497983521890304/STEM/21a6217a24ef416f81bc7d70de4abc6f.png?resizew=207)
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名校
【推荐3】问题提出
![](https://img.xkw.com/dksih/QBM/2020/6/12/2482828415229952/2484737831370752/STEM/80be7f720f024ea2a4a4e74f4f30d560.png?resizew=443)
(1)如图①,在正方形ABCD中,对角线AC=8,则正方形ABCD的面积为 ;
问题探究
(2)如图②,在四边形ABCD中,AD=AB,∠DAB=∠DCB=90°,∠ADC+∠ABC=180°,若四边形ABCD的面积为8,求对角线AC的长;
问题解决
(3)如图③,四边形ABCD是张叔叔要准备开发的菜地示意图,其中边AD和AB是准备用砖来砌的砖墙,且满足AD=AB,∠DAB=90°,边DC和CB是准备用现有的长度分别为3米和7米的竹篱笆来围成的篱笆墙,即DC=3米,CB=7米.按照这样的想法,张叔叔围成的菜园里对角线AC的长是否存在最大值呢?若存在,求出这个最大值;若不存在,说明理由.
![](https://img.xkw.com/dksih/QBM/2020/6/12/2482828415229952/2484737831370752/STEM/80be7f720f024ea2a4a4e74f4f30d560.png?resizew=443)
(1)如图①,在正方形ABCD中,对角线AC=8,则正方形ABCD的面积为 ;
问题探究
(2)如图②,在四边形ABCD中,AD=AB,∠DAB=∠DCB=90°,∠ADC+∠ABC=180°,若四边形ABCD的面积为8,求对角线AC的长;
问题解决
(3)如图③,四边形ABCD是张叔叔要准备开发的菜地示意图,其中边AD和AB是准备用砖来砌的砖墙,且满足AD=AB,∠DAB=90°,边DC和CB是准备用现有的长度分别为3米和7米的竹篱笆来围成的篱笆墙,即DC=3米,CB=7米.按照这样的想法,张叔叔围成的菜园里对角线AC的长是否存在最大值呢?若存在,求出这个最大值;若不存在,说明理由.
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解答题-问答题
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【推荐1】在平面直角坐标系xOy中,
的半径为1.对于点A和线段BC,给出如下定义,若将线段BC绕点A旋转可以得到
的弦
(
,
分别是B,C的对应点),则称线段BC是
的以点A为中心的“关联线段”.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/25/3dabfe30-3a17-4315-9337-837ae8b37108.png?resizew=484)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/25/f0f96c3d-ad99-48d6-9d97-099649628325.png?resizew=281)
(1)如图,点A,C,
,
的横、纵坐标都是整数.在线段AC,
,中,
的以点A为中心的“关联线段”是_________;
(2)
是等腰直角三角形,
,
,点
,其中
.着BC是
的以点A为中心的“关联线段”,求t的值;
(3)在
中,
,
.若BC是
的以点A为中心的“关联线段”,直接写OA的最小值和最大值,以及相应的BC长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e737bc35da650eda3825d29799b5f86f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4c8a9c4957431681ddfc77895a88508.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/25/3dabfe30-3a17-4315-9337-837ae8b37108.png?resizew=484)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/25/f0f96c3d-ad99-48d6-9d97-099649628325.png?resizew=281)
(1)如图,点A,C,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/564a094212a6ae5e14bef8fec5442bdf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8191696f0d5986796bd5d310b6af6d75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02055f5f6f677b9052aedcd1c97140f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f89deb952f57f4b3fa4887b098b7b91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c704999a090103f18c8e1b46ededca35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/823ab696d27d40920c39b8c910789380.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(3)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70dc2c20619a4fc12a0cfda59af5b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
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解答题-问答题
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解题方法
【推荐2】如图,在平面直角坐标系中,抛物线y=﹣
x2+bx+3的对称轴是直线x=2,与x轴相交于A,B两点(点A在点B的左侧),与y轴交于点C.
![](https://img.xkw.com/dksih/QBM/2022/2/24/2923424521945088/2927041955708928/STEM/146bab3978b045da939f7958bb43ced4.png?resizew=233)
(1)求抛物线的解析式及顶点坐标;
(2)M为第一象限内抛物线上的一个点,过点M作MN⊥x轴于点N,交BC于点D,连接CM,当线段CM=CD时,求点M的坐标;
(3)以原点O为圆心,AO长为半径作⊙O,点P为⊙O上的一点,连接BP,CP,求2PC+3PB的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
![](https://img.xkw.com/dksih/QBM/2022/2/24/2923424521945088/2927041955708928/STEM/146bab3978b045da939f7958bb43ced4.png?resizew=233)
(1)求抛物线的解析式及顶点坐标;
(2)M为第一象限内抛物线上的一个点,过点M作MN⊥x轴于点N,交BC于点D,连接CM,当线段CM=CD时,求点M的坐标;
(3)以原点O为圆心,AO长为半径作⊙O,点P为⊙O上的一点,连接BP,CP,求2PC+3PB的最小值.
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【推荐1】已知:直线y=x+6交x轴于A点,交y轴于C两点,经过A和原点O的抛物线y==ax2+bx(a<0)的顶点B在直线AC上.
(1)求点A、C、B的坐标
(2)求出抛物线的函数关系式;
(3)以B点为圆心,以AB为半径作⊙B,将⊙B沿x轴翻折得到⊙D,试判断直线AC与⊙D的位置关系,并求出BD的长;
(4)若E为⊙B优弧
上一动点,连结AE、OE,问在抛物线上是否存在一点M,使∠MOA︰∠AEO=2︰3,若存在,试求出点M的坐标;若不存在,试说明理由
(1)求点A、C、B的坐标
(2)求出抛物线的函数关系式;
(3)以B点为圆心,以AB为半径作⊙B,将⊙B沿x轴翻折得到⊙D,试判断直线AC与⊙D的位置关系,并求出BD的长;
(4)若E为⊙B优弧
![](https://img.xkw.com/dksih/QBM/2012/8/28/1573501547716608/1573501597278208/STEM/23280c3246194a52983f30b85215886a.png)
![](https://img.xkw.com/dksih/QBM/2014/3/24/1573716676313088/1573716682825728/STEM/fb3e952a-a9dc-4a26-8932-30932723e8f7.png)
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名校
【推荐2】在平面直角坐标系中,
为坐标原点,直线
交
轴于
,交
轴于
,经过
、
两点的抛物线
交
轴于另一点
.
![](https://img.xkw.com/dksih/QBM/2023/9/26/3333202254159872/3333864856985600/STEM/479fa92715914f4890c673e9f82c4519.png?resizew=493)
(1)求抛物线的解析式;
(2)
为抛物线上第四象限上一点,连接
、
、
,设点
的横坐标为
,
的面积为
,求
与
的函数关系式;
(3)在(2)的条件下,点
为抛物线上一点,当
的面积
最大时,
,求点
的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c30056990f61f896705dbe3a1fd9d27c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22e59da5115d0dafea24822245f92c48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://img.xkw.com/dksih/QBM/2023/9/26/3333202254159872/3333864856985600/STEM/479fa92715914f4890c673e9f82c4519.png?resizew=493)
(1)求抛物线的解析式;
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c025ee3317be1099b7bf03a11e37ed4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(3)在(2)的条件下,点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c025ee3317be1099b7bf03a11e37ed4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d554b427633ddcb438830785d380728.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
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