A rectangle is surrounded by a wire with a length of 10 meters. There are the following four situations. Among them, the area of the rectangle formed by making the length of the rectangle more than the width by how many meters is the largest.
用一根长为10米的铁丝围成一个长方形，有下列四种情况，其中使该长方形的长比宽多多少米情况围成的长方形面积最大．
<result>0.4</result>