图中,用数对(2,1),(6,1),(6,4)分别代表点A,B,C的位置,那么线段AC长是 .
==8÷2==36÷ .
==18÷ =.
÷40==0.375=9÷ =.
÷5== (填小数)=15÷ .
8÷ ==0.125= %.