A triangle is formed with a piece of wire, and the ratio of the lengths of the three sides is 4:5:7. It is known that the length of the longest side is 28 cm. How long is this wire in cm?
用一段铁丝围成一个三角形，三条边长度的比是4：5：7．已知最长边的长度是28厘米，这段铁丝长多少厘米？
<gadget id="calculator">4 + 5 + 7</gadget>
<output>16</output>

<gadget id="calculator">7 / 16</gadget>
<output>7/16 = around 0.4375</output>

<gadget id="calculator">28 / (7/16)</gadget>
<output>64</output>

<result>64</result>