There is a circular flower bed with a diameter of 8 meters in the park, and there is a path with a width of 2 meters around the flower bed. What is the area of this gravel path?
公园里有一个直径是8米的圆形花坛，在花坛周围有一条宽2米的小路．这条石子小路的面积是多少？
<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>