Yuhe Ecological Park has a circular flower bed with a diameter of 8 meters, surrounded by a gravel road with a width of 2 meters. What is the area of the gravel road?
御河生态公园有一个直径8米的圆形花坛，周围是一条宽2米的石子路．石子路的面积是多少？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

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

<gadget id="calculator">36 - 16</gadget>
<output>20</output>

<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<result>62.8</result>