![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a6d50515fc65885d44cd6a3c41e6a7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/307773456102f4d7ea664385029acdc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/004fffe57568c3cb76d43794584da944.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4626c693586583b09c3008f1d81a76a.png)
![](https://img.xkw.com/dksih/QBM/2023/9/28/3334579715637248/3335188466778112/STEM/9f6bb0c96dff4862924d63fb14e8406b.png?resizew=330)
![](https://img.xkw.com/dksih/QBM/2023/9/28/3334579715637248/3335188466778112/STEM/83d103b7e5cd4133942c479b9d533daa.png?resizew=225)
(1)若点P在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0664699cab2130e2b8fb5d976848418b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca4678ff1b3ea3bd09ed3494a0efe31c.png)
(2)若点P在边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/780d8fd6c6c1deeeb45e15f639719e02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b69d40b75d582c4b8ffa2369af1d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d57899ad4774aed9ccc7bd23db72153.png)
(3)若点P运动到边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/780d8fd6c6c1deeeb45e15f639719e02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b69d40b75d582c4b8ffa2369af1d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d57899ad4774aed9ccc7bd23db72153.png)
23-24八年级上·全国·课后作业 查看更多[1]
更新时间:2023-09-29 12:41:13
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相似题推荐
解答题-问答题
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适中
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【推荐1】如图,点O在直线AB上,OC平分∠DOB.若∠COB=36°.
![](https://img.xkw.com/dksih/QBM/2016/1/29/1573966446182400/1573966452318208/STEM/bfd5a7b7cb20476cb15b300161c6523d.png)
(1)求∠DOB的大小;
(2)求∠AOC的大小.
![](https://img.xkw.com/dksih/QBM/2016/1/29/1573966446182400/1573966452318208/STEM/bfd5a7b7cb20476cb15b300161c6523d.png)
(1)求∠DOB的大小;
![](https://img.xkw.com/dksih/QBM/2016/1/29/1573966446182400/1573966452318208/STEM/482c1a42e34e44188f3f4d785d5a43e8.png)
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【推荐2】如图所示,已知点O为直线
上一点,射线
平分
,射线
平分
,请写出图中有互余关系的角、互补关系的角各3对.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fed1f57a835af4e9022e27603d12d31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75f55c6ac896ab4277fae2230a6e10b0.png)
![](https://img.xkw.com/dksih/QBM/2020/9/22/2555277387841536/2555322145906688/STEM/47c7fee6-0f5d-4d37-b432-0fa21d2f16d6.png)
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解答题-作图题
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适中
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【推荐1】在
中,
,
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/1/d0c2984a-707f-4fda-8f16-281de827b818.png?resizew=100)
(1)用直尺和圆规作
的平分线
交
于点D(保留作图痕迹,不要求写作法.)
(2)在(1) 的条件下,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d59ae599c3e37765826272420b5eecb9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/1/d0c2984a-707f-4fda-8f16-281de827b818.png?resizew=100)
(1)用直尺和圆规作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0d801edd85c816522ae1e40b83ae9ba.png)
(2)在(1) 的条件下,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a72dfbf0138a611174c36ce077e0c47.png)
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解答题-证明题
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【推荐2】已知:在△AOB和△COD中,OA=OB,OC=OD.
![](https://img.xkw.com/dksih/QBM/2021/12/5/2866140469190656/2867222158893056/STEM/c96c103a-d22a-4f0a-9236-5d766748eb38.png?resizew=456)
(1)如图1,若∠AOB=∠COD=60°,
求证:①AC=BD;
②∠APB=60°.
(2)如图2,若∠AOB=∠COD=α,则AC与BD间的等量关系式为 ,∠APB的大小为 .
![](https://img.xkw.com/dksih/QBM/2021/12/5/2866140469190656/2867222158893056/STEM/c96c103a-d22a-4f0a-9236-5d766748eb38.png?resizew=456)
(1)如图1,若∠AOB=∠COD=60°,
求证:①AC=BD;
②∠APB=60°.
(2)如图2,若∠AOB=∠COD=α,则AC与BD间的等量关系式为 ,∠APB的大小为 .
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解答题-问答题
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适中
(0.65)
【推荐1】如图,在
中,
是
边上一点,
是
边上一点,
和
相交于点
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2022/7/6/3016894288248832/3055682208210944/STEM/d38f8b17b7f4461e996950738f6bcce2.png?resizew=147)
求:(1)
的度数;
(2)
的度数,
对于上述问题,在以下解答过程的空白处填上适当的内容(理由或数学式).
解:(1)∵
( ),
∴
(等量代换).
(2)∵
( ),
∴
(等式的性质)
(等量代换)
= .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b8a5b476e7bc3345e2a91f31aae372d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c769090b5a79d9d21f7e9b6a95468b47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa6b5f434dcc8212026b5f5d78a82c3b.png)
![](https://img.xkw.com/dksih/QBM/2022/7/6/3016894288248832/3055682208210944/STEM/d38f8b17b7f4461e996950738f6bcce2.png?resizew=147)
求:(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a72dfbf0138a611174c36ce077e0c47.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95ee1c8b8f17e6adfe29201544ee304c.png)
对于上述问题,在以下解答过程的空白处填上适当的内容(理由或数学式).
解:(1)∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27ca4e0ac739427f343d6b631969850c.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1bea763d6559dac9ab9d8e575153ccd.png)
(2)∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec2ff407e0578a2b11db1f1ff5d1ee9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53e519cdb0cac3981d8e9610dba507a3.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94312c6f5ee60c1fda8e8c7db072a6bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99d045c1d3c1e536be964f1a51f85406.png)
= .
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解答题-证明题
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名校
【推荐2】如图,已知
是等腰直角三角形,
,
是
的平分线,
,垂足为D.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/29/8c78a839-f417-48f8-a268-61efbedb1f57.png?resizew=164)
(1)求证:
;
(2)请你写出图中所有的等腰三角形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bffd657e48b15b9b54a55817e2c26b22.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/29/8c78a839-f417-48f8-a268-61efbedb1f57.png?resizew=164)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4151e948feebdf7b91fbe739feafa9bc.png)
(2)请你写出图中所有的等腰三角形.
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解答题-证明题
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【推荐1】利用“模型”解决几何综合问题往往会取得事半功倍的效果.
几何模型:如图(1),我们称它为“A”型图案,
易证明:∠EDF = ∠A + ∠B + ∠C;
应用上面模型解决问题:
?
分析: 图中
是“A”型图,于是
,
所以
= ;
(2)如图(3),“七角星”形,求
;
(3)如图(4),“八角星”形,可以求得
= ;
几何模型:如图(1),我们称它为“A”型图案,
易证明:∠EDF = ∠A + ∠B + ∠C;
应用上面模型解决问题:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2358bb6d99c5d1e1562dabae4ef6d9b.png)
分析: 图中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e507e50205e5c6cc7483115245610f37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85d30413f931ee1ff4dcc67ef52641cf.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00309f3568eb65a33a215b06138df3e7.png)
(2)如图(3),“七角星”形,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de87b3880ccf0900d1b7023a7ab8d650.png)
(3)如图(4),“八角星”形,可以求得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77f32fd163df566782c21976f4f1ea5c.png)
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【推荐2】现实生活中,各种各样的图形随处可见.我们知道,由不在同一直线上的三条线段首尾顺次相接所组成的图形叫做三角形.由三角形定义可知,在平面内,由若干条不在同一条直线上的线段首尾顺次相连组成的封闭图形叫做多边形.
如图1,若有三条边的叫做三角形,有四条边的叫做四边形,有五条边的叫做五边形
,现在我们类比三角形内角和来研究其他多边形图形的内角和问题.
探究:猜想并验证四边形的内角和.
猜想:四边形内角和为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b2ccc34a8b3cf908af78bdbe804afac.png)
验证:在四边形
中,连接
,则四边形
被分为两个三角形(图
.
所以,四边形
的内角和
的内角和
的内角和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2fb162bb4eca29f27aca9c436a605f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83f319c2a522fa64984577e0f04af2c5.png)
请类比上述方法探究下列问题.
(1)探究:猜想并探究五边形
的内角和.(图![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2324a65e345753fdd1db2354bfb0ee4.png)
猜想:
验证:
(2)根据上述探究过程,可归纳出
边线内角和为 .
(3)证明:①已知一个多边形的内角和为
,那么这是个 边形.
②一天小明爸爸给小明出了一道智力题考考他.将一个多边形截去一个角后(没有过顶点),得到的多边形内角和将会( )
A.不变 B.增加
C.减少
D.无法确定.
如图1,若有三条边的叫做三角形,有四条边的叫做四边形,有五条边的叫做五边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfe639eab78eafd2d40ea70aa5d3f21d.png)
探究:猜想并验证四边形的内角和.
猜想:四边形内角和为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b2ccc34a8b3cf908af78bdbe804afac.png)
验证:在四边形
![](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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad217e26bd3580c35998109de14cef73.png)
所以,四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecc5a4a807ba8a6a72dfc6127e2f82f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2cdf633600b2abf487033a01f1c2156.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2fb162bb4eca29f27aca9c436a605f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83f319c2a522fa64984577e0f04af2c5.png)
请类比上述方法探究下列问题.
(1)探究:猜想并探究五边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2324a65e345753fdd1db2354bfb0ee4.png)
猜想:
验证:
(2)根据上述探究过程,可归纳出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(3)证明:①已知一个多边形的内角和为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b8edfa98ab26e226b6a4aa1f715445.png)
②一天小明爸爸给小明出了一道智力题考考他.将一个多边形截去一个角后(没有过顶点),得到的多边形内角和将会( )
A.不变 B.增加
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfe639eab78eafd2d40ea70aa5d3f21d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfe639eab78eafd2d40ea70aa5d3f21d.png)
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