A new circular flower bed is newly built in the park. Its diameter is 8 meters. What is the floor area of this flower bed?
公园里新建了一个圆形花坛，它的直径是8米，这个花坛的占地面积是多少？
<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>