如果正方形的周长为c,它的边长是 .
0.75===3: = %
﹦24: ﹦ ÷20﹦ %
÷ ==9: = (小数)
÷ == %== : = 折= 成.
= ÷32=( 0.125 )填小数=6:( )=12.5%.