2πrh+75.36=2π*(r+4)*h,h=75.36/(8π)2π*(r+4)*h/2πrh=5/3,r=6v=π*6*6*75.36/(8π)=339.12(cm)^3原来圆柱的体积=339.12(cm)^3
教过,但我忘了