A square is formed by a wire 2 cm long, what is the side length of the square in cm?
用一根长2分米的铁丝围成一个正方形，正方形的边长是多少厘米．
<gadget id="calculator">2 * 10</gadget>
<output>20</output>

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

<result>5</result>