The waist and base of an isosceles triangle are measured as (2/5) decimeters and (7/15) decimeters respectively. How long is the iron wire needed to surround such a triangle?
量得一个等腰三角形的腰和底分别是(2/5)分米和(7/15)分米，要围这样一个三角形至少需要多长的铁丝？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">(2/5) + (2/5) + (7/15)</gadget>
<output>19/15 = around 1.266667</output>

<result>19/15 = around 1.266667</result>