圆柱的侧面积S=2*3.14*r*h=94.2cm², 则3.14*r*h=94.2/2=47.1圆柱的体积v=3.14*r*r*h=235.5cm³r*(3.14*r*h)=235.5r=235.5/47.1=5cm圆柱的底面积S=3.14*r*r=3.14*5*5=78.5cm²答：这个圆柱的底面积78.5...