试一试底面周长:C=∏d=3.14*4=12.56(dm) 底面积:S=∏(d/2)^2=3.14*(4/2)^2=12.56(dm^2) 侧面积:S'=hC=5*12.56=62.8(dm^2) 总面积:S+S'=12.56+62.8=75.36(dm^2)2.压路机压过的痕迹为长方形,长为：3.14*1.2=3.768米,宽...