What is the area of a square frame that is folded from a 40 cm long iron wire?
用一根长40厘米的铁丝折成一个正方形框架，它的面积是多少．
<gadget id="calculator">40 / 4</gadget>
<output>10</output>

<gadget id="calculator">10 * 10</gadget>
<output>100</output>

<result>100</result>