Use an iron wire with a length of 84 cm to make the largest cube frame, what is the length of the sides of the cube in cm?
用一根长84cm的铁丝做成一个最大的正方体框架，这个正方体的棱长是多少cm．
<gadget id="calculator">84 / 12</gadget>
<output>7</output>

<result>7</result>