Xiao Ming makes a triangle with a piece of iron wire. Measure out (2/5) of the full length as the first side, measure out (3/10) of the full length as the second side, and use the third side as the full length of the wire What percentage? What kind of triangle is this?
小明用一根铁丝制作一个三角形，量出全长的(2/5)作第一条边，量出全长的(3/10)作第二条边，第三条边占铁丝全长的几分之几？这是一个什么三角形？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (2/5) - (3/10)</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>