梯形面积课件蒙文VIP免费

2.54.6344cmabhabbha×=÷2×=÷2＋=÷236m120m135mS=（a+b）h÷2=（36+120）×135÷2=156×135÷2=21060÷2=10530（m2）6945S=（a+b）h÷2=(6+9)×4÷2=15×4÷2=30(c㎡)119654S=（a+b）h÷2=(9+11)×4÷2=20×4÷2=40(c㎡)345S=（a+b）h÷2=(3+4)×5÷2=7×5÷2=17.5(c㎡)cm1012.5138.5(1)(13+10)×8.5÷2(3)(13+10)×12.5÷2(2)(8.5+12.5)×13÷2(4)(8.5+12.5)×10÷2⑷⒋⒊⒉⒈√√××4.6m1.5m4.6×1.5÷2=3.45㎡25m10m140m2？χ(25＋10)χ÷2＝14035χ÷2＝14035χ＝140×235χ＝280χ＝280÷35χ＝8140×2÷(25+10)＝140×2÷35＝280÷35＝8（m）SS＝＝(a(a＋＋b)h÷2b)h÷2hh＝＝2S÷(a2S÷(a＋＋bb））aa＝＝2S÷h2S÷h－－bbbb＝＝2S÷h2S÷h－－aa