三角形的面积是34dm3,与它等底等高的平行四边形的面积是 dm2.
× = ÷== %.
27÷ == :2== (填小数)
== ÷12= (小数)
=9: = :20= ÷ a:4=3a: = :4+2.
=4÷ = (填小数)= %