A triangle is formed with 36 cm long iron wire, and the ratio of its three sides is 3:4:5. What is the length of the longest side of this triangle?
用36厘米长的铁丝围成一个三角形，它的三边比为3：4：5，这个三角形最长的边长是多少．
<gadget id="calculator">3 + 4 + 5</gadget>
<output>12</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">36 * (5/12)</gadget>
<output>15</output>

<result>15</result>