在菱形ABCD中,∠BAD=60°,
(1) 如图1,点E为线段AB的中点,连接DE、CE.若AB=4,求线段EC的长;
(2) 如图2,M为线段AC上一点(不与A、C重合),以AM为边向上构造等边三角形AMN,线段MN与AD交于点G,连接NC、DM,Q为线段NC的中点,连接DQ、MQ,判断DM与DQ的数量关系,并证明你的结论;
(3) 在(2)的条件下,若AC=
,请你直接写出DM+CN的最小值.
(1) 如图1,点E为线段AB的中点,连接DE、CE.若AB=4,求线段EC的长;
(2) 如图2,M为线段AC上一点(不与A、C重合),以AM为边向上构造等边三角形AMN,线段MN与AD交于点G,连接NC、DM,Q为线段NC的中点,连接DQ、MQ,判断DM与DQ的数量关系,并证明你的结论;
(3) 在(2)的条件下,若AC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/2019/5/24/2210462728060928/2217533798293504/STEM/11e81a2a9c964e149927a37cb1c8334e.png?resizew=510)
更新时间:2019-06-03 10:46:58
|
相似题推荐
解答题-证明题
|
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【推荐1】(1)【问题探究】如图1,正方形
中,点F、G分别在边
、
上,且
于点P,求证:
;
(2)【知识迁移】如图2,矩形
中,
,
,点E、F、G、H分别在边
、
、
、
上,且
于点P.若
,求
的长;
(3)【拓展应用】如图3,在菱形
中,
,
,点E在直线
上,
,
交直线
于点F.请直接写出线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.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/4cdfa782e70dc979c456f85158152be3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d698d46a9232bd184b2cbb8b185ea6d.png)
(2)【知识迁移】如图2,矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76d527d4795ece4a5756d1cf8dba31e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65e34f3fbb1adf23cf81d7005f4387a6.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/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d94fef6d03173baf154ac97154571366.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9bfba85ffc1061664eb2d3b9fbe913b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23bb85d51b268f349dd633f02d05b05d.png)
(3)【拓展应用】如图3,在菱形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd3cec1a1a669c6498e16f08d1ddff7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35df46d413858ccf400647e117dee605.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b80b71495d98dd3533905407bf31ce23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e3e6500dd5e8afa138fc72a8a8224e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/862730f28c12750ebea0af5edcac5fef.png)
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解题方法
【推荐2】如图1,在平面直角坐标系中,A(8,0),点B在第一象限,△OAB为等边三角形,OC是AB边上的高.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/24/21f7961e-0987-4679-a5ea-58cc2796ceab.png?resizew=605)
(1)则点C的横坐标________;
(2)图2中,作点C关于y轴对称点D,连接DA,DC分别交OB于点E,F,求证:OE=EF.
(3)图3中,在OC上取点M,连接BM,以BM为边向右作等边△BMN,连接AN,CN;
①求证:OA⊥AN;
②当△BCN周长的最小值时,求∠BNC的度数.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/24/21f7961e-0987-4679-a5ea-58cc2796ceab.png?resizew=605)
(1)则点C的横坐标________;
(2)图2中,作点C关于y轴对称点D,连接DA,DC分别交OB于点E,F,求证:OE=EF.
(3)图3中,在OC上取点M,连接BM,以BM为边向右作等边△BMN,连接AN,CN;
①求证:OA⊥AN;
②当△BCN周长的最小值时,求∠BNC的度数.
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名校
【推荐1】
为等边三角形,D为平面内一点,
,
.
(1)如图1,连接
,垂足为F,F为
中点,求
的面积;
(2)如图2,连接
,连接
,取
中点G,连接
交
于点H,K为线段
上一点,
,连接
,求证:
为等边三角形;
(3)如图3,
,P为
中点,连接
,当线段
长度最小时,做点E关于直线
的对称点
,请直接写出此时
的周长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d212c1709b8e72a055cf1b5381ef64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a1b8d111d101afbbf301a2c56c6d15e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/3/96d83ac9-0706-4f42-8b0c-9f9dab30bfa0.png?resizew=593)
(1)如图1,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf5031925378b9c428cc0d6a67f5e808.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
(2)如图2,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a7e4a6765ce78b05ee97764771e01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a16f5621716bfef7a056a3f2712feb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8efcf1fb2092d605e475440b3efb4b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e4c6b0869d7248b6c2f964718a67702.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ae0ea5e99da7b096aed5fb380047e12.png)
(3)如图3,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c394ce4f35865a16b1c58f592731505.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3b1a5427d8ff23df0f3ec194756c84c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccbe9e0d5b3d77268883b804faecf89d.png)
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【推荐2】已知:四边形
中,
,
,
分别为
中点,
相交于点
.
,求证:
.
(2)当
,
时,求
的长;
(3)当
为直角三角形时,线段
与
之间有怎样的数量关系?并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b9477bca655a4eaf7c354cf42abe085.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8dd77e7c5ccc4bade65303461c46277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d82d579a717399137b8c6d475d33cd4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b795e2cfa58b494fd8f5437b3db0d1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4652f95f3a388706906bc85f53f8db1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b75c2ab34d253e38e09505a2059ce06.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/284a563413dc0532138fb2a64db8cc2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a917db13b0c7bb4a4f81c81a970454c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e04521727594e71dcccd976cac40e5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
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【推荐1】如图所示,点P是菱形
对角线
上的一点,连接
并延长
交边
于点E,连接
并延长
交边
于点F,交
的延长线于点G.
![](https://img.xkw.com/dksih/QBM/2021/3/3/2669951577702400/2673547187822592/STEM/22894357-6d0e-4b07-890f-de914018ccd3.png?resizew=182)
(1)求证:
.
(2)若已知
,请确定线段
与线段
之间满足的数量关系.
(3)若
,且当
是等腰三角形时,请直接可出
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/2021/3/3/2669951577702400/2673547187822592/STEM/22894357-6d0e-4b07-890f-de914018ccd3.png?resizew=182)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32d0710321d97361e5782124bbf7f0c9.png)
(2)若已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96ca4fd1fe3b227af1c9d7318ae0ebc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fb26d84907c923278ac4626a9d58947.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4028e972c0e63cb150e1aca85bd163b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/818e85b6d1dba50519ccac5c44c54f8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff53524370518a112d82fb005cc594a0.png)
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解答题-作图题
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【推荐2】综合与实践
数学活动课上,同学们用尺规作图法探究在菱形内部作一点到该菱形三个顶点的距离相等.
【动手操作]如图,已知菱形
,求作点E,使得点E到三个顶点A,D,C的距离相等.小红同学设计如下作图步骤∶
;
②分别以点A,D为圆心,大于
的长为半径分别在
的上方与下方作弧:
上方两弧交于点M,下方两弧交于点N,作直线
交
于点E.
③连接
,
,则
.
(1)根据小红同学设计的尺规作图步骤,在题图中完成作图过程(要求∶用尺规作图并保留作图痕迹)
(2)[证明结论]证明:
.
(3)[拓展延伸]当
时,求
与
的面积比.
数学活动课上,同学们用尺规作图法探究在菱形内部作一点到该菱形三个顶点的距离相等.
【动手操作]如图,已知菱形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
②分别以点A,D为圆心,大于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4cb1a4c5afb590c7c17de14d15651e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
③连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c21fe43b8bfca2c3adb758c1697905fe.png)
(1)根据小红同学设计的尺规作图步骤,在题图中完成作图过程(要求∶用尺规作图并保留作图痕迹)
(2)[证明结论]证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c21fe43b8bfca2c3adb758c1697905fe.png)
(3)[拓展延伸]当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3104c05e255396a91038e2896aedf5cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6818a98204f62c1b16699d26ca0c3f62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cb3e973f4e9361e1d23a0ab56006d12.png)
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解答题-问答题
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【推荐1】如图,
是
的直径,
,点
是
的中点,连接
、
.
是
的半径(点
不与点
重合),点
关于直线
的对称点为点
,连接
、
、
.
(1)
的长为______.(结果保留
)
(2)当点
与点
重合,且点
在
上时,求
所在的扇形的面积.(结果保留π)
(3)当点
在直线
右侧,且
与
的某条直角边平行时,求
的长.
(4)当
时,直接写出
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9774f83067ed956a551bc41adcce0469.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4c8a9c4957431681ddfc77895a88508.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1586d3ecae6747312b7892bac03cf8bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/288abe01824f42cfe725509af5aec4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/9/98dbbea8-0a1b-4322-a640-1c6cc4d71ce8.png?resizew=134)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/667349d99185bb045030b733352ff7fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70f5389990c3a0c5373f3bd9fb2454c9.png)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4c8a9c4957431681ddfc77895a88508.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed41d321f4c0717ac5b443aad942d9a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/900b844294e8c07ea9a858adb845121c.png)
(3)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/900b844294e8c07ea9a858adb845121c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/173bc7a36757d77f01213411edd25241.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/900b844294e8c07ea9a858adb845121c.png)
(4)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4426bda755acfe81ee5b8f4f6cff6c0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/900b844294e8c07ea9a858adb845121c.png)
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解答题-问答题
|
较难
(0.4)
【推荐2】如图,二次函数y1=x2+bx+c与y2=x2+cx+b(b<c)的图象相交于点A,分别与y轴相交于点C,B,连接AB、AC.
(1)过点(1,0)作直线l平行于y轴,判断点A与直线l的位置关系,并说明理由.
(2)当A、C两点是二次函数y1=x2+bx+c图象上的对称点时,求b的值.
(3)当△ABC是等边三角形时,求点B的坐标.
(1)过点(1,0)作直线l平行于y轴,判断点A与直线l的位置关系,并说明理由.
(2)当A、C两点是二次函数y1=x2+bx+c图象上的对称点时,求b的值.
(3)当△ABC是等边三角形时,求点B的坐标.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/3/cc521fba-eac6-43b6-ba6b-91e926074ef5.png?resizew=227)
您最近一年使用:0次