1、112.2.2 三角形全等的判定三角形全等的判定(SAS)第十二章第十二章 全等三角形全等三角形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)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/zilia
2、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/前前 言言
3、学习目标学习目标1.掌握“边角边”条件的内容,并能初步应用“边角边”条件判定两个三角形全等。2.使学生经历探索三角形全等条件的过程,体会如何探索研究问题,并初步体会分类思想,提高学生分析问题和解决问题的能力。3.通过画图、比较、验证,培养学生注重观察、善于思考、不断总结的良好思维习惯。重点难点重点难点重点:掌握“边角边”判定两个三角形全等的方法。难点:掌握“边角边”判定两个三角形全等的方法。3PPT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
4、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
5、ishi/情况1:两边和它们的夹角相等,两三角形全等吗?画一个ABC ,使两边和夹角相等?ABC画法:画法:AB C DE1.画DA E=A;2.在射线A E上截取A C =AC,在射线A D上截取A B =AB;3.连接B C。(三角形三边相等两三角形全等)全等全等思考思考4PPT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
6、: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/由以上尺规作图的方法可以得到以下基本事实:由以上尺规作图的方法可以得到以下基本事实:两边和它们的夹角分别相等
7、的两个三角形全等。(即“边角边”或“SAS”)小结小结5PPT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
8、/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/在在ABC与与DEF中中AB=DEB=EBC=EFABC DEF(SAS)ABCDEF用语言表达如下:用语言表达如下:小结小结6PPT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
9、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/kejian/
10、lishi/情况2:两边和其中一边的对角相等,两三角形全等吗?如图,ABC与ABD中,AB=AB,AC=AD,B=B,他们全等吗?他们全等吗?BACDBADBAC不全等不全等思考思考7PPT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/
11、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/因铺设电线的需要,要在池塘两侧因铺设电线的需要,要在池塘两侧A、B处各埋设一根电线杆(如图),因无法直接量出处各埋设一根电线杆(如图),因无法直接量出A、B两点的距离,现有一足够的米尺请你设计一种方案,
12、粗略测出两点的距离,现有一足够的米尺请你设计一种方案,粗略测出A、B两杆之间的距离两杆之间的距离分析:先在池塘旁取一个能直接到达分析:先在池塘旁取一个能直接到达A和和B处的点处的点C,连结,连结AC并延并延长至长至D点,使点,使DC=AC,连结,连结BC并延长至并延长至E点,使点,使EC=BC,连结,连结DE,用米尺测出用米尺测出DE的长,这个长度就等于的长,这个长度就等于A,B两点的距离请你说明两点的距离请你说明理由理由 AC=DC ACB=DCE BC=EC ACB DCE AB=DE对顶角相等思考思考8PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beij
13、ing/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:om/kejian/huaxue/
14、生物课件:om/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/ABDO1.在下列推理中填写需要补充的条件,使结论成立:在下列推理中填写需要补充的条件,使结论成立:(1)如图如图,在在AOB和和DOC中中AO=DO(已知已知)_=_()BO=CO(已知已知)AOB DOC()AOB DOC对顶角相等对顶角相等CSAS课堂测试课堂测试9PPT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
15、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/kejian
16、/lishi/(2)如图,在如图,在AEC和和ADB中,已知中,已知AE=AD,AC=AB,请说明,请说明AEC ADB的理由。的理由。AEBDC_=_(已知已知)A=A(公共角公共角)_=_(已知已知)AEC ADB()AEADACAB解:在解:在AEC和和ADB中中SAS课堂测试课堂测试10PPT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/j
17、iaoan/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/(SAS)AD=BC.请说明理由。请说明理由。AD=BC()课堂测试课堂测试11PPT模板
18、: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/kexue/物理课件
19、: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/ABCD3.已知:如图已知:如图AB=CB,ABD=CBD,ABD和和CBD全等吗?全等吗?(SAS)课堂测试课堂测试12PPT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/
20、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,AC=BD,CAB=DBA,你能判断,你能判
21、断BC=AD吗?说明理由吗?说明理由ABCDC (SAS)课堂测试课堂测试13PPT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
22、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/ABCDFE1.如图如图,已知已知AB=DE,AC=DF,要说明要说明ABC DEF,还需增加一个,还需增加一个什么条件?什么条件?1.BE=CF(SSS)2.A=D(SAS)(答案不唯一)探索提高探索提高14PPT模板:om/moban/PPT素材:om/sucai/PPT背景:om/beijing/PP
23、T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:o
24、m/kejian/shengwu/地理课件:om/kejian/dili/历史课件:om/kejian/lishi/FCBEDA2.如图如图:己知己知ADBC,AE=CF,AD=BC,E、都在直线上,试、都在直线上,试说明说明。A D D+A DEF EF(内错角相等两直线平行内错角相等两直线平行)探索提高探索提高15PPT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/shi
25、ti/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/2.如图,如图,AC=BD,1=2 求证求证:BC=AD变式变式1
26、:如图,如图,AC=BD,BC=AD求证求证:1=2ABCD12ABCD12变式变式2:如图,如图,AC=BD,BC=AD求证求证:C=DABCD探索提高探索提高16PPT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
27、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/ABCD变式变式3:如图,如图,AC=BD,BC=AD求证求证:A=B探索提高探索提高17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)