The perimeter of a sheet of iron is 108 cm. Cut out a square from each of its four corners and fold it into a square iron box without a lid. What is the volume of the iron box in cubic centimeters?
一张铁皮的周长是108厘米，在它的四角分别剪去一个正方形，折做成一个无盖的正方体铁盒，这个铁盒的容积是多少立方厘米？
<gadget id="calculator">108 / 4 / 3</gadget>
<output>9</output>

<gadget id="calculator">9 * 9 * 9</gadget>
<output>729</output>

<result>729</result>