Build a circular path with a width of 1m outside a circular fish pond with a diameter of 8 meters. What is the area occupied by this circular path?
在一个直径是8米的圆形鱼池外修一条宽1m的环形小路，这条环形小路的占地面积是多少？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

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

<gadget id="calculator">25 - 16</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>