Teacher Wang surrounded a triangle with a 1-meter-long iron wire. The length of one side of the triangle is (1/5) meters, and the length of the other side is (2/5) meters. How many meters is the length of the third side? What kind of triangle is this?
王老师用一根1米长的铁丝围了一个三角形，量得三角形的一边长是(1/5)米，另一边长是(2/5)米，第三条边长多少米？这是一个什么三角形？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/5) - (2/5)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>