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1、学习好资料欢迎下载本课的名称：直线、射线和角教学内容：人教版义务教育课程标准实验教科书数学四年级（上册）第 35、36 页。教学目标：1、让学生进一步认识线段，认识射线和直线，知道线段、射线和直线的区别；进一步认识角，知道角的含义，能用角的符号表示角。2、使学生经历观察、画图和交流等活动，初步感悟：从一点出发可以画无数条射线，经过一点可以画无数条直线，经过两点只能画一条直线。3、培养学生观察、操作、比较和抽象、概括的能力。4渗透事物之间相互联系和变化的观点。教学过程：一、联系生活，引出直的线谈话：我们的生活就象一个五彩缤纷的万花筒，今天我们探究的数学知识就藏在这画里，画面上藏着许多线，大家找找
2、看。1.展示彩灯的图片提问：请你用数学的眼光观察这张图片，你有什么发现？预设：学生可能会说发现光线或射线。措施：若学生发现光线则追问学生：光线从哪里射出来的？并展开想象：假如有无穷的能量，而且没有障碍，它可以射多远？有没有尽头？若学生发现射线（板书），先追问：射线在哪里？再展开想象。学习好资料欢迎下载2.联系生活展示手电筒光线，车灯光线和阳光的光线的图片。小结：这些线有的是直的，有的是弯曲的，今天我们就一起到线王国里找找我们的老朋友吧！二、线的研究1、课件出示线段：你对线段有哪些了解呢？学生交流说说线段的特 2、课件演示：把线段一端的端点去掉，引出射线提问：认真观察，这一端会发生什么变化？（演
3、示：把一端延长）现在你看到的还是一条线段吗？组织交流讨论（或许会说出是射线）讲述：我们得到一种新的线，只有一个端点，可以向一端无限延伸，这样的线我们把它叫做射线。强调：射怎么理解？（回答：射箭，灯光照射等）设计意图：教学以线段为基础引出射线，通过动态多媒体演示使学生直观感知，形成表象，初步建立空间观念。谈话：射线其实在我们的生活中并不陌生。演示：打开手电筒光线射向掌心移开手掌将光投至墙壁，感知光线可以不断延长。引导：如果老师把手移开，光线会发生什么变化？（光会照射到墙上）谈话：如果不受任何阻碍，想像一下，这束光线将会穿越天空，冲出云层，穿过宇宙这束光线它长吗？手电筒的光源灯泡我们就可以把它近似
4、地看作一个端点，它射出的光线向外无限延伸，像这样的光线就可以看作是射线。文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:C
5、P9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:
6、CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码
7、:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编
8、码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档
9、编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文
10、档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2文档编码:CP9V10G3G10P9 HH10H5R6U7W7 ZN1H8B4S8H2
11、学习好资料欢迎下载提问：生活中还有象这样一端可以无限延长的现象吗？提问：我们认识了射线，那谁能说说射线是什么样的？板书：射线谈话：我们的新区盛元广场大家去过吗？那里的夜景美丽极了，我们一起来欣赏一下吧：（课件显示）一束束绚丽的灯光把广场的夜空装扮得格外美丽，你能从中找出我们熟悉的线朋友吗？（学生可以找出射线、直线和线段以及曲线等）其实只要善于观察，作个有心人，你就会发现数学就在我们身边！3、认知直线谈话：在生活中我们找到了线段和射线，还有一些曲线，可是有一种在我们生活中很熟悉但却很不好找的线，它在数学王国了有很重要的位置，大家能猜出它是谁吗？想不想认识它的样子？课件演示：动画延伸直线板书：直线
12、4、合作交流：探究三线的联系与区别提问：每种线都有各自的特点，那么它们有什么区别与联系呢？下面需要大家认真观察、讨论，找出它们的区别与联系。活动之前请看清楚要求。课件出示活动要求：4 人小组分工合作，团结探索先画出三线的图示，再交流三线的区别与联系图例端点个数 长度文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4
13、O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D
14、9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10
15、HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8
16、O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编
17、码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2
18、E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10
19、 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10学习好资料欢迎下载线段射线直线小组汇报后教师小结三线的区别（课件出示）线段：两个端点，可以度量长度射线：一个端点，向一方无限延伸直线：没有端点，向两边无限延伸提问：通过大家的观察比较，发现三种线有各自的特点，我们再来一起研究一下，直线、射线和线段之间有什么联系呢？（课件动态演示）学生交流讨论（略）小结：射线和
20、线段都来自于直线，射线和线段都是直线的一部分。设计意图：通过看一看、说一说、找一找、比一比等一系列活动，使学生能深刻体验射线的特征，自觉地将射线与生活中的现象联系在一起，同时利用直观动态演示，突出了三种线之间的联系，加深了对线段、射线、直线等概念的理解。5、学以致用说一说（判断并说明理由）课件出示6、学以致用画一画根据刚才的探究，我们知道射线和直线都可以延伸，画的时候不能画完，所以只需要画出一部分就可以了，我们来比试一下，画一画吧！文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E
21、2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B1
22、0 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8
23、H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I
24、6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:C
25、J10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X
26、10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA
27、4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10学习好资料欢迎下载a 通过一点画直线，大家猜想一下，过这一点你能画多少条直线？我们试试看，看你在20 秒内可以画多少条！（学生活动）在心里数
28、数，你画了多少条？看来20 秒内画的条数不一样，有的孩子画的快，就多画了几条。那大家想想，如果时间不限制，你可以画多少条？如果时间可以无限多，那你可以画多少条。那说明，通过一点的直线有多少条呢？（课件显示）b 出示 2 点画直线，大家猜猜要同时经过这两点，可以画多少条直线？学生画一画汇报结果，课件显示结果。过两点的直线只有一条。c 有了刚才的经验，那么猜一猜，通过一点的射线有多少条？课件显示：过一点可以画无数条射线。小结：过一点可以作出无数条射线。d 从一点起可以画出无数条射线，现在请大家画一点，然后从这一点开始只画两条射线，（指名学生到黑板上画，其余学生在练习纸上画）设计意图：陶行知曾说“知
29、者行之始，行者，知之成”，弗赖登塔尔也强调，数学教学的具体组织过程，应该通过学生自己的亲身体验，获得“做出来”的数学，而不是给以“现成的”数学。基于以上的认识，于过一点可以画无数条直线，过两点只能画一条直线，老师不是直接告诉学生，而是让学生先猜测再动手画一画，这样“做”出来的数学学生是终身难忘的。同时通过一点可以画无数条射线到只画两条射线，很自然的就过渡到了下一个环节角的形成。三、角的研究1、引出角的概念文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ1
30、0V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10
31、文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O
32、6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9
33、B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 H
34、M8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O
35、2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码
36、:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10学习好资料欢迎下载谈话：观察有公共端点的这些射线，你能从中发现隐藏的图形吗？（角）通过刚才画角，想想你的角是怎么画成的？学生交流后，（课件演示角的动态形成过程）小结：从
37、一点引出两条射线所组成的图形叫作角。设计意图：由具有公共端点的射线自然引出角的认识，将学生的视线从整体引向部分，突出主体部分，学生会看到一个角。这样的安排一方面自然过渡到“角的认识”的教学，另一方面又让学生实实在在地看到了角的形成过程。学生看书学习角的各部分名称和角的记法交流汇报自学的知识，教师板书角的知识2、组织作角，理解角的大小和角的两边叉开程度有关。学生操作：利用手中的练习纸折出角，比一比同桌 2 人谁折的角大操作讨论：你有办法使角变大吗？提问：由次可知，角的大小与什么有关系呢？小结：角的大小与角的两边叉开的大小有关四、小结收获，运用新知通过今天的学习，你都学到了哪些知识？你想提醒同学们
38、记住哪些知识呢？（板题：直线、射线和角）设计意图：课堂总结不但让学生回顾本节课所学知识，还引导学生反思自己的学习过程和方法，向同伴提出忠告，有利于学生更好地积累数学经验，获得学习方法，提高学习能力。五、拓展延伸（1）数出下图中有几个角？文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:C
39、J10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X
40、10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA
41、4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2
42、D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10
43、 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V
44、8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档
45、编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10学习好资料欢迎下载（2）找出下图中有哪些线，各有几条？设计意图：练习设计具有层次性、针对性和综合性，有助于学生对知识的理解，开拓了学生视野，培养学生解决问题的能力。附：板书设计直线、射线和角线段1 点射线角2 条文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 H
46、M8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O
47、2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码
48、:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E
49、5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10
50、ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8L2D9B10 ZA4O6E2E5X10文档编码:CJ10V8O2I6F10 HM8H8