A piece of iron wire can make a rectangle with a length of 8 decimeters and a width of 2 decimeters. If this wire is used to make a square, what is the area of the square?
一根铁丝能做一个长8分米，宽2分米的长方形，如果用这根铁丝做一个正方形，正方形的面积是多少平方分米？
<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

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

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<result>25</result>