1、1 3.1.1 轴 对 称轴 对 称第第13章章 轴对称轴对称Please Enter Your Detailed Text Here,The Content Should Be Concise And Clear,Concise And Concise Do Not Need Too Much Text人教版 数学(初中)(八年级 上)PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试
2、卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/前前 言言学习目标学习目标1.能够识别简单的轴
3、对称图形、成轴对称的图形及其对称轴、对称点,能指出轴对称图形和成轴对称的图形的对称轴。2.能说出轴对称图形与成轴对称的图形的区别与联系。重点难点重点难点轴对称图形及成轴对称的图形的区别与联系。PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kej
4、ian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/观察这些图像有什么共同特点?观察观察PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/
5、PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejia
6、n/dili/历史课件:om/kejian/lishi/1.请同学们准备一张纸;请同学们准备一张纸;2.首先对折纸;首先对折纸;3.展开你的想象力,在纸上画出你想要画的图案;展开你的想象力,在纸上画出你想要画的图案;4.然后沿线条剪下;然后沿线条剪下;5.把纸张展开,欣赏你的杰作。把纸张展开,欣赏你的杰作。动手操作动手操作PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/s
7、hiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/观察观察PPT模板:om/moban/PPT素材:om/suc
8、ai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:o
9、m/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/轴对称图形轴对称图形 如果一个平面图形沿着一条直线折叠,直线两旁的部分能够完全重合,那么就如果一个平面图形沿着一条直线折叠,直线两旁的部分能够完全重合,那么就称这个图形为轴对称图形称这个图形为轴对称图形。这条直线就是他的对称轴轴对称图形对称轴PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/
10、资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejia
11、n/lishi/你能举出一些轴对称图形的例子吗?举例举例PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian
12、/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/思考思考PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报
13、:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/u把一个图形沿着某一条直线折叠,如果它能够与另一个图形重合,那么称这把一个图形沿着某一条直线折叠,如果它能够
14、与另一个图形重合,那么称这两个图形两个图形关于这条关于这条直直线(成轴)对称。线(成轴)对称。u这条直线叫做这条直线叫做对称轴对称轴。u折叠后重合的点叫折叠后重合的点叫对应点,对应点,也叫也叫对称点对称点。对称轴对称轴ABCACB对称点对称点成轴对称、对称轴、对称点成轴对称、对称轴、对称点PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiao
15、an/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/轴对称图形两个图形成轴对称区别联系 一个一个特殊图形特殊图形两个图形的特殊关系沿一条直线折叠,直
16、线两旁的部分能够互相重合。互相重合。都有对称轴。对称轴。把成轴对称的两个图形看成一个整体,它就是一个轴对称图形;把一个轴对称图形分成两个图形,这两个图形关于这条直线对称。小结小结PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuw
17、en/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/已知图中的两个三角形关于直线已知图中的两个三角形关于直线MN对称,点对称,点A、B、C分别是点分别是点A、B、C的对称点,线段的对称点,线段AA与直线与直线MN有什么关系?有什么关系?BB,CC与直线与直线M
18、N呢?呢?MABCCA线段线段AA被直线被直线MN 垂直平分垂直平分.直线直线MN叫做线段叫做线段AA的的垂直平分线垂直平分线.N思考思考PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/sh
19、uxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/经过线段中点并且垂直于这条线段的直线,叫做这条线段的垂直平分线垂直平分线。垂直平分线概念垂直平分线概念PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/x
20、iazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om
21、/kejian/dili/历史课件:om/kejian/lishi/1.如果两个图形关于某条直线对称,那么如果两个图形关于某条直线对称,那么对称轴对称轴是任何一对对应点所连线段的是任何一对对应点所连线段的垂直平分线垂直平分线.2.类似地,轴对称图形的类似地,轴对称图形的对称轴对称轴,是任何一对对应点所连线段的,是任何一对对应点所连线段的垂直平分线垂直平分线.lABAB图形轴对称的性质图形轴对称的性质PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/
22、资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejia
23、n/lishi/1.下下面的图形是轴对称图形吗面的图形是轴对称图形吗?如果是,你能找出对称轴吗?如果是,你能找出对称轴吗?是是是不是不是课堂测试课堂测试PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/ke
24、jian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/2.图中三角形(图中三角形(4)与哪些三角形成轴对称?)与哪些三角形成轴对称?整个图形是轴对称图形吗?它们共有几条对称轴?整个图形是轴对称图形吗?它们共有几条对称轴?43211和3是2条课堂测试课堂测试PPT模板:om/moban/P
25、PT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/ziliao/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/
26、wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/3.如图,两个四边形关于直线如图,两个四边形关于直线l对称,对称,C90,试写出,试写出a,b的长度,并求出的长度,并求出G的度数的度数l解:a=5 cm b=4 cm G=55课堂测试课堂测试PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om/xiazai/PPT教程:om/powerpoint/资料下载:om/zilia
27、o/个人简历:om/jianli/试卷下载:om/shiti/教案下载:om/jiaoan/手抄报:om/shouchaobao/PPT课件:om/kejian/语文课件:om/kejian/yuwen/数学课件:om/kejian/shuxue/英语课件:om/kejian/yingyu/美术课件:om/kejian/meishu/科学课件:om/kejian/kexue/物理课件:om/kejian/wuli/化学课件:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/4.如图,如图,ABC是轴对称图形,且直线是轴对称图形,且直线AD是是ABC的对称轴,点的对称轴,点E,F是线段是线段AD上的任意两上的任意两点,若点,若ABC的面积为的面积为12,求图中阴影部分的面积之和,求图中阴影部分的面积之和 阴影部分的面积和为6课堂测试课堂测试