1 .
与
有公共顶点
(顶点均按逆时针排列),
,
,
,
,点
是
的中点,连接
并延长交直线
于点
,连接
.
![](https://img.xkw.com/dksih/QBM/2019/12/27/2364201175433216/2367062939262976/STEM/e3138aa1724744e0b7dd032db33f3654.png?resizew=253)
(1)如图,当
时,
求证:①
;
②
是等腰直角三角形.
(2)当
时,画出相应的图形(画一个即可),并直接指出
是何种特殊三角形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bd3b58d32346a8d31bc90adc67d37b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d831c9ba6d18774540e2aaa29132fec9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aabd1d9b7e7f7ecb788ff542218af2b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95a078495ba47076ccaa28b46f765d80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c50cabc089584cf0ee7a12e0bf60caa.png)
![](https://img.xkw.com/dksih/QBM/2019/12/27/2364201175433216/2367062939262976/STEM/e3138aa1724744e0b7dd032db33f3654.png?resizew=253)
(1)如图,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
求证:①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc382c4f315de17f293d3d273626ade2.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae969dfd9f4fae0fbff6bc4dc02812b6.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fdd2a3642716fcf5100011eb3ec88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae969dfd9f4fae0fbff6bc4dc02812b6.png)
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2019-12-31更新
|
407次组卷
|
3卷引用:辽宁省鞍山市台安县2019-2020学年八年级上学期第二次阶段测试数学试题
辽宁省鞍山市台安县2019-2020学年八年级上学期第二次阶段测试数学试题(已下线)考点15 等腰三角形与直角三角形《备战2020年中考核心考点清单》河南省周口市鹿邑县2019-2020学年八年级上学期期末数学试题
2 . 如图,等腰
中,
,
,
于点
,点
是
延长线上一点,点
是线段
上一点,
.下列结论:①
;②
;③
是等边三角形;④
.其中正确结论的个数是( )
![](https://img.xkw.com/dksih/QBM/2019/12/6/2349528178098176/2350563231236096/STEM/7bac13e7-c0d5-44ca-885f-d08eefcc41de.png?resizew=149)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f86c589939053ce21ce0a67cf40054a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1ccccc58e9149d75ba341f9f4b4d506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/817034645f62424337ace509145e24d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2cce190fb2e9724236a1c5c5d657722.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9dc427a01582ec222446b352d40ab0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95ce869fa3e84a19978a568cda75789c.png)
![](https://img.xkw.com/dksih/QBM/2019/12/6/2349528178098176/2350563231236096/STEM/7bac13e7-c0d5-44ca-885f-d08eefcc41de.png?resizew=149)
A.1 | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2019-12-08更新
|
603次组卷
|
2卷引用:湖南省长沙市一中教育集团2019-2020学年八年级12月月考数学试题
3 . 如图1,△ABC的AB边为圆O的弦,AC、BC分别交圆O于D、E,弧AD=弧BE,∠C=60°;
![](https://img.xkw.com/dksih/QBM/2019/11/27/2342800929914880/2343458178695169/STEM/1d9636fdef5347e7820661695735eb9e.png?resizew=486)
(1)求证:△ABC为等边三角形;
(2)如图2,F为弧AD上一点,连接FE并延长至G,连接BG,若∠AFB=∠G,求∠FBG的正弦值;
(3)如图3,在(2)的条件下,连接FC并延长交BG延长线于H,若CF=CH,AF=7,HG=12,求线段BF的长度.
![](https://img.xkw.com/dksih/QBM/2019/11/27/2342800929914880/2343458178695169/STEM/1d9636fdef5347e7820661695735eb9e.png?resizew=486)
(1)求证:△ABC为等边三角形;
(2)如图2,F为弧AD上一点,连接FE并延长至G,连接BG,若∠AFB=∠G,求∠FBG的正弦值;
(3)如图3,在(2)的条件下,连接FC并延长交BG延长线于H,若CF=CH,AF=7,HG=12,求线段BF的长度.
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4 . 在下列结论中:①有三个角是
的三角形是等边三角形;②有一个外角是
的等腰三角形是等边三角形;③有一个角是
,且是轴对称的三角形是等边三角形;④有一腰上的高也是这腰上的中线的等腰三角形是等边三角形.其中正确的是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
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5 . 定义:有个内角为
,且对角线相等的四边形称为准矩形.
![](https://img.xkw.com/dksih/QBM/2019/11/13/2333096158208000/2333940091822080/STEM/77f7bb20-d3f7-49f1-b6a7-f6ebbe2f6fcc.png)
(1)如图1,准矩形ABCD中.
,若
,
,则
_____;
(2)如图2,直角坐标系中,
,
,若整点P使得四边形AOBP是准矩形,则点P的坐标是______;(整点指横坐标、纵坐标都为整数的点)
(3)已知,准矩形ABCD中,
,
,
,当
为等腰三角形时,请求出这个准矩形的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://img.xkw.com/dksih/QBM/2019/11/13/2333096158208000/2333940091822080/STEM/77f7bb20-d3f7-49f1-b6a7-f6ebbe2f6fcc.png)
(1)如图1,准矩形ABCD中.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c978d92edf0c4c1ef8620c17df75d35e.png)
(2)如图2,直角坐标系中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f94c4f6b762fddb0e313050ef6932eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54fe2c124d5bbbbe666ee145cd454b6b.png)
(3)已知,准矩形ABCD中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fdd2a3642716fcf5100011eb3ec88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7ac5396c5ea442e0364b50c1db3d2da.png)
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6 . 已知:如图,△AOB的顶点O在直线上,且AO=AB.
(1)画出△AOB关于直线成轴对称的图形△COD,且使点A的对称点为点C;
(2)在(1)画出的图形中,AC与BD的位置关系是 ;
(3)在(1)画出的图形中连接AD,如果∠ABD=2∠ADB.
求证:△AOC是等边三角形,并直接写出∠DAO∶∠DAB的值.
(1)画出△AOB关于直线成轴对称的图形△COD,且使点A的对称点为点C;
(2)在(1)画出的图形中,AC与BD的位置关系是 ;
(3)在(1)画出的图形中连接AD,如果∠ABD=2∠ADB.
求证:△AOC是等边三角形,并直接写出∠DAO∶∠DAB的值.
![](https://img.xkw.com/dksih/QBM/2019/11/12/2332379428618240/2332982664732672/STEM/7410ad9579fe45bba973cbd59770576d.png?resizew=108)
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7 . 如图,已知线段
,按照以下要求作图和证明:用尺规作等边
;在
的延长线上取点
,在
的延长线上取点
,使得
,连接
,
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38efab2b954882d5d6b664b2a8d4c879.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4546ca9391c8ad8107d93b898819cacf.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/df1ac3ab8d3ce5e61fd2f89761f80976.png)
![](https://img.xkw.com/dksih/QBM/2019/10/29/2322511143673856/2322573598539776/STEM/51578fb03805435e88ff205072f34439.png?resizew=114)
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8 . 如图,在直角坐标系中,点A,B分别在x,y轴上,点C是OB的中点,BE,CD都与x轴平行,BD⊥AB,∠ABO=30°.
![](https://img.xkw.com/dksih/QBM/2019/10/25/2319596804907008/2320346947887105/STEM/154a91e066ad4b54aab8cf91bef17fc2.png?resizew=182)
(1)判断△OBD的形状;
(2)若A(-3,0),BE=6,求证OE=AD.
![](https://img.xkw.com/dksih/QBM/2019/10/25/2319596804907008/2320346947887105/STEM/154a91e066ad4b54aab8cf91bef17fc2.png?resizew=182)
(1)判断△OBD的形状;
(2)若A(-3,0),BE=6,求证OE=AD.
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9 . 已知:如图,△ABC为等边三角形,AB
=
,AH⊥BC,垂足为点H,点D在线段HC上,且HD=2,点P为射线AH上任意一点,以点P为圆心,线段PD的长为半径作⊙P,设AP=x.
![](https://img.xkw.com/dksih/QBM/2019/9/12/2289204510547968/2290057352347648/STEM/d0ed9414060c4486b9a7d611655e8193.png?resizew=490)
(1)当x=3时,求⊙P的半径长;
(2)如图1,如果⊙P与线段AB相交于E
、F两点,且EF=y,求y关于x的函数解析式,并写出它的定义域;
(3)如果△PHD与△ABH相似,求x的值(直接写出答案即可).
![](https://img.xkw.com/dksih/QBM/2019/9/12/2289204510547968/2290057352347648/STEM/23aab791bded42bbba304af8c1d01949.png?resizew=3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41322821ce31416fdac8dd6e0aa41c71.png)
![](https://img.xkw.com/dksih/QBM/2019/9/12/2289204510547968/2290057352347648/STEM/d0ed9414060c4486b9a7d611655e8193.png?resizew=490)
(1)当x=3时,求⊙P的半径长;
(2)如图1,如果⊙P与线段AB相交于E
![](https://img.xkw.com/dksih/QBM/2019/9/12/2289204510547968/2290057352347648/STEM/cfb96d5f21754230aaa5596dc3af0834.png?resizew=3)
(3)如果△PHD与△ABH相似,求x的值(直接写出答案即可).
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2019-09-13更新
|
398次组卷
|
2卷引用:吉林省长春六中2019年中考模拟数学试题(6月份)
10 . 如图1,已知等边△ABC中,动点P、Q分别从点A、B出发,以同样速度沿边AB、BC向终点B、C运动.D为AC中点,AQ、CP交于点O,连接OB、OD.
(1)∠AOP的度数是 .
(2)如图2,当点P运动到AB边的中点时,求证:OB=2OD;
(3)若点P不在中点时,OB=2OD还成立吗?请说明理由.
(1)∠AOP的度数是 .
(2)如图2,当点P运动到AB边的中点时,求证:OB=2OD;
(3)若点P不在中点时,OB=2OD还成立吗?请说明理由.
![](https://img.xkw.com/dksih/QBM/2019/5/14/2203429097242624/2206470148046848/STEM/e5505745ad1642d9a727ee61dbb7422b.png?resizew=351)
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