If a 72 cm long iron wire is used to make a cuboid frame with a width of 4 cm and a height of 6 cm, what is the length in cm?
如果用一根长72厘米的铁丝做一个宽4厘米，高6厘米的长方体框架，长是多少厘米？
<gadget id="calculator">72 / 4</gadget>
<output>18</output>

<gadget id="calculator">18 - 4 - 6</gadget>
<output>8</output>

<result>8</result>