如图,在
中,
是
的高,点D为边
上的一点,连接
.
(1)当
为边
上的中线时,若
,求
的面积.
(2)当
为
的角平分线时,若
,求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/7/b30674ae-252b-444f-b26b-488d8c2faa27.png?resizew=177)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99a28a15c71044c8696f6b56b12e2d6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)当
![](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/62c53358a4560f3c96e95b65205f2710.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57e7106619c08f2bcc1d21f846e8a0de.png)
更新时间:2023-09-12 23:30:48
|
相似题推荐
解答题-作图题
|
适中
(0.65)
【推荐1】如图,每个小正方形的边长为1个单位,每个小方格的顶点叫格点.△ABC的顶点都在方格纸格点上.
![](https://img.xkw.com/dksih/QBM/2022/4/28/2967767676698624/2970930849251328/STEM/feba7f51-ede3-4109-b8f1-d7e230fc6676.png?resizew=226)
(1)请在图中画出ABC先向上平移3个单位,再向左平移2个单位后的△A1B1C1;
(2)图中AC与A1C1的关系是_______ ;
(3)图中△ABC的面积是 ;
(4)请利用三角尺,画出△A1B1C1边B1C1上的高A1D,垂足为点D.
![](https://img.xkw.com/dksih/QBM/2022/4/28/2967767676698624/2970930849251328/STEM/feba7f51-ede3-4109-b8f1-d7e230fc6676.png?resizew=226)
(1)请在图中画出ABC先向上平移3个单位,再向左平移2个单位后的△A1B1C1;
(2)图中AC与A1C1的关系是_______ ;
(3)图中△ABC的面积是 ;
(4)请利用三角尺,画出△A1B1C1边B1C1上的高A1D,垂足为点D.
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解答题-问答题
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适中
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【推荐1】如图,
是
边
的中点,连接
并延长到点
,使
,连接
.
和 成中心对称;
(2)已知
的面积为
,则
的面积是 .
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e786c5e1b0bb46acb5e8e910bf16fe99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7ac5396c5ea442e0364b50c1db3d2da.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7ac5396c5ea442e0364b50c1db3d2da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
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解答题-作图题
|
适中
(0.65)
【推荐2】图①、图②、图③都是5×5的网格,每个小正方形的顶点称为格点,△
的顶点均在格点上,在图①、图②、图③给定网格中,仅用无刻度的直尺,按下列要求完成画图,并保留作图痕迹.
(1)在图①中边
上找到格点
,并连接
,使
将△
面积两等分;
(2)在图②中△
的内部找到格点
,并连接
、
,使△
是△
面积的
.
(3)在图③中△外部画一条直线
,使直线
上任意一点与
、
构成的三角形的面积是△
的
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(1)在图①中边
![](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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)在图②中△
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
(3)在图③中△外部画一条直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ca8b26c3ad6d892590290a2304126bd.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/2/5d4edba3-6b2b-47c0-8072-0158a00955e3.png?resizew=501)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐3】探索:在图1至图3中,已知△ABC的面积为a,
![](https://img.xkw.com/dksih/QBM/2016/5/13/1574206319443968/1574206325522432/STEM/fe9fd67e61e34ef4a9b0b05a1aa7a018.png)
(1)如图1,延长△ABC的边BC到点D,使CD=BC,连接DA.若△ACD的面积为S1,则S1=________(用含a的代数式表示)
(2)如图2,延长△ABC的边BC到点D,延长边CA到点E,使CD=BC,AE=CA,连接DE.若△DEC的面积为S2,则S2=________(用含a的代数式表示)
(3)在图2的基础上延长AB到点F,使BF=AB,连接FD,FE,得到△DEF(如图3).若阴影部分的面积为S3,则S3=________(用含a的代数式表示).
发现:像上面那样,将△ABC各边均顺次延长一倍,连接所得端点,得到△DEF(如图3),此时,我们称△ABC向外扩展了一次.可以发现,扩展一次后得到的△DEF的面积是原来△ABC面积的__ __倍.
应用:要在一块足够大的空地上栽种花卉,工程人员进行了如下的图案设计:首先在△ABC的空地上种红花,然后将△ABC向外扩展三次(图4已给出了前两次扩展的图案).在第一次扩展区域内种黄花,第二次扩展区域内种紫花,第三次扩展区域内种蓝花.如果种红花的区域(即△ABC)的面积是10平方米,请你运用上述结论求出:
(1)种紫花的区域的面积;
(2)种蓝花的区域的面积.
![](https://img.xkw.com/dksih/QBM/2016/5/13/1574206319443968/1574206325522432/STEM/fe9fd67e61e34ef4a9b0b05a1aa7a018.png)
(1)如图1,延长△ABC的边BC到点D,使CD=BC,连接DA.若△ACD的面积为S1,则S1=________(用含a的代数式表示)
(2)如图2,延长△ABC的边BC到点D,延长边CA到点E,使CD=BC,AE=CA,连接DE.若△DEC的面积为S2,则S2=________(用含a的代数式表示)
(3)在图2的基础上延长AB到点F,使BF=AB,连接FD,FE,得到△DEF(如图3).若阴影部分的面积为S3,则S3=________(用含a的代数式表示).
发现:像上面那样,将△ABC各边均顺次延长一倍,连接所得端点,得到△DEF(如图3),此时,我们称△ABC向外扩展了一次.可以发现,扩展一次后得到的△DEF的面积是原来△ABC面积的__ __倍.
应用:要在一块足够大的空地上栽种花卉,工程人员进行了如下的图案设计:首先在△ABC的空地上种红花,然后将△ABC向外扩展三次(图4已给出了前两次扩展的图案).在第一次扩展区域内种黄花,第二次扩展区域内种紫花,第三次扩展区域内种蓝花.如果种红花的区域(即△ABC)的面积是10平方米,请你运用上述结论求出:
(1)种紫花的区域的面积;
(2)种蓝花的区域的面积.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在四边形
中,
,对角线
与
相交于点
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/5/1d90b529-2291-45f7-834f-220ac9da7f13.jpg?resizew=221)
(1)求证:
平分
;
(2)若
,且
,
平分
交
边于点
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.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/3ed1b0a312e0ddf54abbbade60f2ca21.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/5/1d90b529-2291-45f7-834f-220ac9da7f13.jpg?resizew=221)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32f34f55889ebc0f945270beb94f98b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/847c3d6a96fd48180d52a1872d0dd2a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/868ff1350bd72625328c85c3097cd85e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa38f3db59cee9d3750e27baf5f8bfdf.png)
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解答题-证明题
|
适中
(0.65)
【推荐2】AB和AC相交于点A,BD和CD相交于点D,探究∠BDC与∠B、∠C、∠BAC的关系,小明是这样做的:
解:如图(2)以点A为端点作射线AD
∵∠1是△ABD的外角
∴∠1=∠B+∠BAD
同理∠2=∠C+∠CAD
∴∠1+∠2=∠B+∠BAD+∠C+∠CAD
即∠BDC=∠B+∠C+∠BAC
小英的思路是:如图(3)延长BD交AC于点E.
![](https://img.xkw.com/dksih/QBM/2021/11/1/2841928181972992/2843123073318912/STEM/65370d0c-ac5c-4877-8cc4-9f3dafa1a21a.png)
(1)按小英的思路完成∠BDC=∠B+∠C+∠BAC这一结论.
(2)如图:△ABC中,BO、CO分别是∠ABC与∠ACB的角平分线,且BO、CO相交于点O.猜想∠BOC与∠A有怎样的关系,并加以证明.
解:如图(2)以点A为端点作射线AD
∵∠1是△ABD的外角
∴∠1=∠B+∠BAD
同理∠2=∠C+∠CAD
∴∠1+∠2=∠B+∠BAD+∠C+∠CAD
即∠BDC=∠B+∠C+∠BAC
小英的思路是:如图(3)延长BD交AC于点E.
![](https://img.xkw.com/dksih/QBM/2021/11/1/2841928181972992/2843123073318912/STEM/65370d0c-ac5c-4877-8cc4-9f3dafa1a21a.png)
(1)按小英的思路完成∠BDC=∠B+∠C+∠BAC这一结论.
(2)如图:△ABC中,BO、CO分别是∠ABC与∠ACB的角平分线,且BO、CO相交于点O.猜想∠BOC与∠A有怎样的关系,并加以证明.
![](https://img.xkw.com/dksih/QBM/2021/11/1/2841928181972992/2843123073318912/STEM/b1d250f6-42c2-46a4-8a57-09fbbe1215c6.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】如图1,在平面直角坐标系中,
是
轴正半轴上一点,
是第四象限内一点,
轴交
轴负半轴于
,且
,
.
(1)求点
的坐标.
(2)如图2,设
为线段
上一动点,当
时,
的角平分线
与
的角平分线
的反向延长线交于点
,求
的度数;(点
在
轴的正半轴).
(3)如图3,当点
在线段
上运动时,作
交
于
点,
、
的角平分线
、
交于
点,则点
在运动过程中,
的大小是否会发生变化?若不变化,求出其值;若变化,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80fe80cadc7049534072aea8c5c8fada.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7d21f72aca4a8a9a188aec99dd631d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78d34bd2e10b34e4149f6459b5ac5196.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76ea8aacea1d46e06b89fe19a49f5ed0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c16b1064c827c6172a2095bb615cee38.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/20/82ff981d-8d27-42f7-b9cc-b94b9a0bbfa4.jpg?resizew=471)
(1)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)如图2,设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35333abd7f02d663d15251bc5cbbf921.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/062c8a3aeb0ff11efde9752e168221d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35803969509655f72b4118503ae1c966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42fa5dff377ef08e416547def489def0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(3)如图3,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf0c62372c5280eb86ebe3aca3f1bc08.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/ed2884b46c0b3b258154b393777e966a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fba1315d450c8353c6611785f71546b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86bfa0bbe05b01453e6ed15d74da2602.png)
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解答题-问答题
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适中
(0.65)
【推荐2】如图,在△ABC中,CD是∠ACB的角平分线,CE是AB边上的高,若∠DCE=10°,∠A=50°,求∠B的度数.
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