利用图形这一直观性语言,在一定程度上可以降低我们认识和理解抽象逻辑推理的难度;利用图形建构几何直观,可以轻松实现空间形式和数量关系的相互转化.让我们在如下的问题解决中体验一下吧!
如图1,求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd05e8542a4afb53a104876b7a057cc5.png)
(2)【直观应用】
①应用上述结论,若图2中,
,则
、
、
、
、
、
的度数之和等于________.(直接给出结论,不必说明理由)
②应用上述结论,求图3所示的五角星中,
、
、
、
、
的度数之和是多少?并证明你的结论.
(3)【类比联系】
如图4,求
、
、
、
、
、
、
的度数之和是多少?并证明你的结论.
如图1,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd05e8542a4afb53a104876b7a057cc5.png)
(2)【直观应用】
①应用上述结论,若图2中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f2244b4f11ee60e474c05882bf8f3fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194741f4d2ae7ee44cafca780361446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c543c3ddc3723fde6bbfca3ea3b921b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b871a762469393cdd22f15aa49ebb8f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50e8c257f5615d30660cef4157c6b273.png)
②应用上述结论,求图3所示的五角星中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194741f4d2ae7ee44cafca780361446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c543c3ddc3723fde6bbfca3ea3b921b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b871a762469393cdd22f15aa49ebb8f9.png)
(3)【类比联系】
如图4,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194741f4d2ae7ee44cafca780361446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c543c3ddc3723fde6bbfca3ea3b921b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b871a762469393cdd22f15aa49ebb8f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50e8c257f5615d30660cef4157c6b273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1e0a272aa29c4531aac22f28c64baf5.png)
22-23七年级下·四川内江·期末 查看更多[5]
四川省内江市2022-2023学年七年级下学期期末数学试题山东省青岛第六十五中学2022-2023学年八年级下学期开学考试数学试题(已下线)专题11.8 三角形章末拔尖卷-2023-2024学年八年级数学上册举一反三系列(人教版)(已下线)专题1.11 三角形的初步知识章末拔尖卷-2023-2024学年八年级数学上册举一反三系列(浙教版)安徽省六安市金安区六安皋城中学2023-2024学年八年级下学期期中数学试题
更新时间:2023-07-24 15:53:01
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,
,
为定点,
,
分别是
,
上的动点,
(1)如图1,求证:
;
![](https://img.xkw.com/dksih/QBM/2020/11/6/2586992818364416/2587963231272960/STEM/a309635d4eb64ddb8bd61794aeee7254.png?resizew=136)
(2)如图2,若
为
上一点,
,且
交
于点
,请判断
与
的关系,并证明你的结论;
![](https://img.xkw.com/dksih/QBM/2020/11/6/2586992818364416/2587963231272960/STEM/f646b926a9c94b6d9e50fa2761f22189.png?resizew=142)
(3)如图3,移动
、
使得
,作
,则
与
有什么数量关系.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
(1)如图1,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d571dea491270a1b766314e6246cda7.png)
![](https://img.xkw.com/dksih/QBM/2020/11/6/2586992818364416/2587963231272960/STEM/a309635d4eb64ddb8bd61794aeee7254.png?resizew=136)
(2)如图2,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31b94298f81a2d776313afc7181cf17f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fb26d84907c923278ac4626a9d58947.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfa70e7c9ef8b856b494d370b7d76482.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72b6b12ebb934efc5bef6ae9a5b16239.png)
![](https://img.xkw.com/dksih/QBM/2020/11/6/2586992818364416/2587963231272960/STEM/f646b926a9c94b6d9e50fa2761f22189.png?resizew=142)
(3)如图3,移动
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05fd792376c623d8299f554b46486f79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa5fb9e2af992fffe98dd3aceb7a68f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/482e68d608de7675e15bb759acd8204c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94d5b88cdac96fd5aeb53283673fafe9.png)
![](https://img.xkw.com/dksih/QBM/2020/11/6/2586992818364416/2587963231272960/STEM/a28bd6eee19f4334984d2cb6994298aa.png?resizew=142)
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解答题-作图题
|
适中
(0.65)
【推荐2】在
中,
,点D、E分别是边
、
上的点(不与A、B、C重合)点P是平面内一动点(P与D、B不在同一直线上),设
,
,
.
![](https://img.xkw.com/dksih/QBM/2022/10/14/3087511223451648/3095529084067840/STEM/15747b36ce1a4854b7e7fecf35bf039b.png?resizew=550)
(1)若点P在边
上运动(不与点B和点C重合),如图(1)所示,则
=______;(用含有
、
的代数式表示)
(2)若点P在
的外部,如图(2)所示,则
、
、
之间有何关系?写出你的结论,并说明理由.
(3)当点P在边CB的延长线上运动时,试画出相应图形,标注有关字母与数字,直接写出对应的
、
、
之间的关系式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e702e136211878dce558e0457f15df63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72939b6fbb10f6bdedf0defc7199cc64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0cfac6f9f64c57fe6464c89ba34c695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cd5a65ee1fee3ce4e48b300696e7688.png)
![](https://img.xkw.com/dksih/QBM/2022/10/14/3087511223451648/3095529084067840/STEM/15747b36ce1a4854b7e7fecf35bf039b.png?resizew=550)
(1)若点P在边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d57899ad4774aed9ccc7bd23db72153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b69d40b75d582c4b8ffa2369af1d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/605f2976297a0deaa1602ef09d6a5afa.png)
(2)若点P在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b69d40b75d582c4b8ffa2369af1d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d57899ad4774aed9ccc7bd23db72153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/605f2976297a0deaa1602ef09d6a5afa.png)
(3)当点P在边CB的延长线上运动时,试画出相应图形,标注有关字母与数字,直接写出对应的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b69d40b75d582c4b8ffa2369af1d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d57899ad4774aed9ccc7bd23db72153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/605f2976297a0deaa1602ef09d6a5afa.png)
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解答题-问答题
|
适中
(0.65)
【推荐1】汛期即将来临,防汛指挥部在某水域一危险地带两岸各安置了一探照灯,便于夜间查看河水及两岸河堤的情况.如图,灯A射出的光束自
顺时针旋转至
便立即回转,灯B射出的光束自
顺时针旋转至
便立即回转,两灯不停交叉照射巡视.若灯A射出的光束转动的速度是
,灯B射出的光束转动的速度是
,且a、b满足
.假定这一带水域两岸河堤是平行的,即
,且
.
(2)如图2,两灯同时转动,在灯A射出的光束到达
之前,过C作
交
于点D,若
,求
的度数;
(3)若灯B射线先转动30秒,灯A射出的光束才开始转动,在灯B射出的光束到达
之前,A灯转动几秒,两灯的光束互相平行?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6ede9761b5b90f8dc137708e1ee90f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8c7f600650d16361ecdfd7aab4ea8b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af29c07a8911da4e054d2f1452392050.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c28d65cd0d51b1e7f7c66550a1e8218d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7928198bde37727e3a04a7f3e6b306fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3e603d5cbbd35815bbfd2b83574e86f.png)
(2)如图2,两灯同时转动,在灯A射出的光束到达
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bfa14df2e34162f35f421f2ae598cc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df44656a8c8e03c7c3452e30455fc219.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
(3)若灯B射线先转动30秒,灯A射出的光束才开始转动,在灯B射出的光束到达
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6ede9761b5b90f8dc137708e1ee90f.png)
您最近一年使用:0次