一个平行四边形的底是2厘米,高是2厘米,这个平行四边形的面积是 .
20: = ÷20==0.8= %
==36÷ = (填小数)
18: =0.25= %= ÷24=.
2.5==50÷ = ÷50.
6: = %=0.25= ÷48= (填分数)