If a square is formed by 8 decimeters of wire, what is the area of the square?
用8分米长的铁丝围成一个正方形，正方形的面积是多少平方分米．
<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>