两个正方形的边长之比是2:3,它们的周长之比是 ,面积之比是 .
:16==24÷ = %
9÷ = :48=0.75= %= 折数.
:12=6÷ = 填小数= 折=75%.
=0.4==12÷ = %= :25.
= (小数)= (百分数)=12: = 折.