如图所示,已知S△ABC=1,FE=EC,AF=AB,则阴影部分的面积为 .
12: =0.375=45÷ = :56=.
15:90= %==6÷ = :12.
=:0.5= ÷ .
:8===9÷ =27: .
=== ÷5=.