There is a circular flower bed in Guangming District. Now build a gravel road with a width of 1m along its outer edge. It is known that the radius of the flower bed is 3m. Find the area of the gravel road.
光明小区有一个圆形花坛．现在沿着它的外沿修-条宽1m的石子路，已知花坛的半径是3m，求石子路面的面积．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

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

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">16 - 9</gadget>
<output>7</output>

<gadget id="calculator">3.14 * 7</gadget>
<output>21.98</output>

<result>21.98</result>