What is the area of a square whose perimeter is 200 cm?
周长是200厘米的正方形，它的面积是多少平方分米．
<gadget id="calculator">200 / 4 / 10</gadget>
<output>5</output>

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

<result>25</result>