What is the area of a square pool with a perimeter of 64 meters?
周长是64米的一个正方形水池，它的面积是多少．
<gadget id="calculator">64 / 4</gadget>
<output>16</output>

<gadget id="calculator">16 * 16</gadget>
<output>256</output>

<result>256</result>