已知长方体表面积是148cm2,底面面积是30cm2,底面的周长是22cm,则这个长方体的体积是 cm3.
12: == :4=0.25= 折.
=2: =4÷ = %=0.2.
12÷ = :12=0.75= = %
0.75=6÷ = :12== %
1.75=7÷ ==28÷ =.