A circular flower bed has a diameter of 8 meters. There is a path with a width of 1 meter around it. What is the area of the path in square meters?
一个圆形花坛，直径是8米，在它的周围有一条宽1米的小路，小路的面积是多少平方米．
<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>