有一块梯形木板,上底比下底多0.6米,上底是1.8米,高比下底少0.9米,这块木板的面积是 .
18: == %=1.8= ÷40.
= : = ÷25= %
5÷2= = :12= %.
= 0. (小数)= :25.
=0.6= ÷10=12: = %= 折.