The diameter of a circular flower pond is 8 meters, how many square meters does this flower pond occupy?
一个圆形花池的直径是8米，这个花池占地多少平方米？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<result>50.24</result>