A rectangle with a length of 2 decimeters and a width of 4 cm is surrounded by an iron wire. If this iron wire is used to form a square, what is the area of the square?
用一根铁丝围成一个长是2分米，宽是4厘米的长方形，如果用这根铁丝围成一个正方形，那么这个正方形的面积是多少．
<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">20 + 4</gadget>
<output>24</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">24 * (1/2) * 24 * (1/2)</gadget>
<output>144</output>

<result>144</result>