1、11.1.3 三角形的稳定性三角形的稳定性第十一章第十一章 三角形三角形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/jia
2、nli/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/前前 言言学习目标学习目标1、通过观
3、察和实践得出三角形具有稳定性,四边形不具有稳定性。2、能判断一般图形是否具有稳定性。3、熟悉和了解三角形的稳定性在生活实际中的一些应用。重点难点重点难点重点:三角形的稳定性。难点:三角形稳定性在实际生活中的应用。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
4、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/生活中常见的图形生活中常见的图形PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om
5、/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:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:
6、om/kejian/dili/历史课件:om/kejian/lishi/如图,盖房子时,在窗框未安装好之如图,盖房子时,在窗框未安装好之前,木工师傅常常先在窗框上斜钉一根前,木工师傅常常先在窗框上斜钉一根木条,为什么要这样做呢?木条,为什么要这样做呢?问题问题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/shouc
7、haobao/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/如图,工程建筑中经常采用三角如图,工程建筑中经常采用三角形的结构,如屋顶钢架,其中的形的结构,如屋顶钢架,其中的道理是什么?道
8、理是什么?问题问题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/meishu/科学课件:om/kej
9、ian/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/1、用三根木条用钉子钉成一个三角形木架,然后扭动它,它的形状会改变吗?、用三根木条用钉子钉成一个三角形木架,然后扭动它,它的形状会改变吗?用手左右扭动三角形木框,形状不发生改变。探究探究1PPT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/po
10、werpoint/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
11、:om/kejian/lishi/2、用四根木条用钉子钉成一个四边形木架,然后扭动它,它的形状会改变吗?、用四根木条用钉子钉成一个四边形木架,然后扭动它,它的形状会改变吗?左右扭动后,四边形的形状发生改变。探究探究2PPT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
12、/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/2、用四根木条用钉子钉成一个四边形木架,然后扭动它,它的形状会改变吗?、用四根木条用钉子钉成一个四边形木架,然后扭动它,它的形状会改变吗?左右扭动后,四边形的形状发生改变
13、。探究探究2PPT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/meishu/科学课件:om/kejian
14、/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/3、在四边形的木架上再钉一根木条,将它的一对顶点连接起来,然后扭动它,它的形状会、在四边形的木架上再钉一根木条,将它的一对顶点连接起来,然后扭动它,它的形状会改变吗?改变吗?用手左右扭动加固后的四边形木框,形状不发生改变。探究探究3PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PPT图表:om/tubiao/PPT下载:om
15、/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:om/kejian/huaxue/生物课件:om/kejian/shengwu/地理课件:
16、om/kejian/dili/历史课件:om/kejian/lishi/三角形木架的形状不会改变,而四边形木架的形状会改变。三角形是具有稳定性的图形,而四边形没有稳定性。结论结论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/“只要三角形三条边的长度固定,这个三角形的形状和大小也就完全确定,三角形的这种性质叫做。”这就是说,三角形的稳定性不是“拉得动、拉不动”的问题,其实质实质应是“三角形边长确定,其形状和大小就确定了”。理解三角
18、形的稳定性理解三角形的稳定性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/meishu/科学课件:o
19、m/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/为什么这个四边形的木架形状不会改变?这是因为钉入一根木条后,四边是变成两个三角形,由于三角形有稳定性,斜钉一根木条的窗框在未安装好之前也不会变形。问题问题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
20、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/kejian/l
21、ishi/找出图形中的三角形找出图形中的三角形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/meis
22、hu/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/木质活动挂架木质活动挂架伸缩门伸缩门四边形不稳定性的应用四边形不稳定性的应用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
23、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/1.人站在晃动的公共汽车上人站在晃动的公共汽车上,
24、若你分开两腿站立若你分开两腿站立,则需伸出一只手去抓住栏杆才能站稳则需伸出一只手去抓住栏杆才能站稳,这是利这是利用了用了_.三角形的稳定性三角形的稳定性课堂测试课堂测试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
25、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/如图,工人师傅砌门时,如何操作,使其不变形,这种做法的根据是_.ABCDEFG三角形的稳定性三角形的稳定性课堂测试课堂测试PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/P
26、PT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:om/kejian/huaxue/生物课件:
27、om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/课堂测试课堂测试造房子的屋顶常用三角形结构,从数学角度来看,是应用了_,而活动接架则应用了四边形的_.三角形的稳定性三角形的稳定性四边形的不稳定性四边形的不稳定性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
28、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/下列图形中具有稳定性有 A.2个B.3个C.4个D.5个分析:分析:1和和3中的由若干四边形组成,不具有稳
29、定性。中的由若干四边形组成,不具有稳定性。2、4、5是由若干三角形组成的图形是由若干三角形组成的图形具有稳定性。具有稳定性。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/kejian/s
30、huxue/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/分组讨论:想想我们生活中日常见到的图形中还有哪些实例运用了三角形稳定性的性质?小组讨论小组讨论感谢各位的仔细聆听感谢各位的仔细聆听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)