There is a concrete road with a width of 1 meter outside a circular flower bed with a diameter of 6 meters. Find the area of this cement road.
一个直径为6米的圆形花坛外有一条宽1米的水泥路，求这条水泥路的面积．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

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

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

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

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

<gadget id="calculator">50.24 - 28.26</gadget>
<output>21.98</output>

<result>21.98</result>