To make a cuboid frame with a base perimeter of 20 cm and a height of 5 cm, at least how many centimeters of iron wire is needed.
做一个底面周长是20厘米，高5厘米的长方体框架，至少需要多少厘米长的铁丝．
<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">40 + 20</gadget>
<output>60</output>

<result>60</result>