假设底面半径为r,高为h,有方程组2rh = 960πr²h/2 = 3014.4化简得rh = 480r²h = 1920解得r = 4,h = 120因此原来钢材的体积为V = πr²h = 6028.8立方厘米侧面积S = 2πrh = 3014.4平方厘米.做到后面才...有道理！