A square flower pond. The perimeter is 64 meters, what is its area in square meters?
一个正方形的花池．周长是64米，它的面积是多少平方米．
<gadget id="calculator">64 / 4</gadget>
<output>16</output>

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

<result>256</result>