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Cliquez pour modifier le style du titre,Cliquez pour modifier les styles du texte du masque,Deuxime niveau,Troisime niveau,Quatrime niveau,Cinquime niveau,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,4.3.2-2角的运算,B,本作业,已知:如图,AOC=BOD=90,,,BOC=40,,求,AOD=?,o,C,B,A,D,解:,AOD=,AOB+,BOC+,COD=140,AOC=90,,,BOC=40,AOB=50,又 ,BOD=90,BOC=40,COD=50,50,50,40,角的度量单位:度、分、秒,.,度,分,秒,60,60,3600,60,3600,60,1,的,60,分之一为,1,分,记作“,1”,,即,1,60,1,的,60,分之一为,1,秒,记作“,1”,,即,1,60,复习回顾一、角的度量单位,1.,角大小的比较方法(观察法、叠合法、度量法)。,2.,角的和差,:,3.,角的平分线的性质。,复习回顾二、角的大小的比较,A,C,O,B,AOB+,BOC=,AOC,AOCAOB=BOC,AOC,=2AOB=2,BOC,AOB=,BOC=,1/2,AOC,例,1,:填空,(,1,),34.5,0,=,0,/,(,2,),112.27,0,=,0,/,/,解:(,1,),34.5,0,=34,0,+0.5,0,=34,0,+0.5,60,/,=34,0,+3 0,/,=34,0,30,/,(,2,),112.27,0,=112,0,+0.2760,/,=112,0,+16.2,/,=112,0,+16,/,+0.260,/,=112,0,16,/,12,/,34,30,112,16,12,题型一:角度的换算,例,2,、把下列各题结果化成度,72,0,36,/,(2)37,0,14,/,24,/,解,:(1)72,0,36,/,=72,0,+36,/,=72,0,+(3660),0,=72,0,+0.6,0,=72.6,0,(2)37,0,14,/,24,/,=37,0,+14,/,+24,/,=37,0,+14,/,+(24,60),/,=37,0,+14,/,+0.4,/,=37,0,+14.4,/,=37,0,+(14.460),0,=37,0,+0.24,0,=37.24,0,例,3,、加减法计算,(1)12,0,36,/,56,/,+45,0,24,/,35,/,解,:(1),原式,=(12+45),0,+(36+24),/,+(56+35),/,=57,0,+60,/,+91,/,=57,0,+61,/,+31,/,=58,0,+1,/,+31,/,=58,0,1,/,31,/,题型二:角度的加减法运算,(2)79,0,45,/,61,0,48,/,49,/,解,:,原式,=79,0,44,/,60,/,61,0,48,/,49,/,=78,0,104,/,60,/,61,0,48,/,49,/,=(78-61),0,(104-48),/,(60-49),/,=17,0,56,/,11,/,例,4,、乘除法运算,(3)21,0,31,/,27,/,3,解,:,原式,=(213),0,(313),/,(273),/,=63,0,93,/,81,/,=63,0,94,/,21,/,=64,0,34,/,21,/,题型三:角度的乘除法运算,(4)63,0,21,/,39,/,3,解,:,原式,=(633),0,(213),/,(393),/,=21,0,7,/,13,/,(5)106,0,6,/,25,/,5,解,:,原式,=(1065),0,(65),/,(255),/,=21,0,(,66,5),/,(255),/,=21,0,13,/,(,85,5),/,=21,0,13,/,17,/,题型三:角度的乘除法运算,例,5,:计算,例题讲解,=825936,解(,1,),=3738+4521.6,=3738+452136,解,=3236,=4660-1424,=,(,46-14,),(,60-24,),=,(,37+45,),(,38+21,),36,例,1,:如图,O,是直线,AB,上一点,AOC=5317BOC,度数,A,O,B,C,分析:(,1,),AB,是直线,AOB,是什么角,?,(,2,),BOC,、,AOB,、,AOC,之间有什么关系,?,AOB,是平角,等于,180,AOB=BOC+AOC,解:,BOC=AOB-AOC=180-5317,=12643,例题讲解,例题讲解,例,2,:把一个周角,7,等分,每一份角是多少度,?,(精确到分),解,:,3607=,51+,37,=51+,180 7,51+,26,即,5126,(,1,),233125,423756,;,(,2,),423156,233725,;,(,3,),2331253,;,(,4,),3607,练习题组,课本,141,页第,2,、,3,题注意第,3,题的步骤!,小结与归纳,1,度、分、秒都是,60,进制,逢,60,进,1,;,加减法要将度与度、分与分、秒与秒分别加减,,分秒相加逢,60,要进位,相减时要借,1,当作,60,;,(借,1,作,60,;借,1,作,60,),3,乘法运算度分秒同时分别乘;,除法先从度开始除,除不尽转化为分,再,除不尽转化为秒,直到精确到要求的位数为止;,此课件下载可自行编辑修改,仅供参考!感谢您的支持,我们努力做得更好!谢谢,
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