Teacher Wang wants to make a cuboid teaching aid with wire. The length is 30cm, the width is 10cm, and the height is 20cm. How many centimeters of iron wire should be used to make this teaching aid?
王老师要用铁丝做一个长方体教具．长30cm，宽10cm，高20cm，做这个教具至少要用多少厘米铁丝？
<gadget id="calculator">30 + 10 + 20</gadget>
<output>60</output>

<gadget id="calculator">60 * 4</gadget>
<output>240</output>

<result>240</result>