组合体的体积40cm40cm9cm9cm72cm30cm30cm同桌讨论,尝试解答8cm9cm40cm72cm10cm8cmabc解: V a = abh = 9×40×8 = 2880( cm3 ) Va = Vb Va+Vb =2880×2=5760 ( cm3 ) V c = abh = 72×10×8 =5760 ( cm3 ) 5760 + 5760 =11520 ( cm3 )答:这个铸铁零件的体积是 11520 立方厘米
8cm 9cm30cm8cm10cmabc解: V a = abh = 9×30×8 =2160 ( cm3 ) Va = Vb Va+Vb=2160×2=4320 ( cm3 ) Vc = abh =(72+9+9)×10×8 = 90×10×8 =7200 ( cm3 ) 72+9+9 = 90cm 4320 + 7200 =11520 ( cm3 )答:这个铸铁零件的体积是 11520 立方厘米
a解: Va = abh = (72+9+9)×40×8 = 90 ×40×8 = 28800 ( cm3 )b Vb = abh = 72×30×8 = 17280 ( cm3 ) 28800 - 17280 = 11520 ( cm3 )答:这个铸铁零件的体积是 11520 立方厘米
302026 9试一试: 求下列组合体的体积 ( 单位: cm )(1)1025146411(2)abab解: Va = abh = (30-9)×10×26 = 27 ×10×26 = 7020 ( cm3 )Vb = abh = 9×20×26 = 4680 ( cm3 ) 7020 + 4680 = 11700 ( cm3 )答:这个组合体的体积是 11700 cm3
解: Va = abh = 6×14×11 = 924 ( cm3 )Vb = ab