The diameter of a circular flowerbed is 20 meters, and a cement road with a width of 1 meter is to be built around the flowerbed. How many square meters does this road cover?
一个圆形花圃的直径是20米，现要绕着花圃修一条宽1米的水泥路．这条路的占地面积是多少平方米？
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">11 ** 2</gadget>
<output>121</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">121 - 100</gadget>
<output>21</output>

<gadget id="calculator">3.14 * 21</gadget>
<output>65.94</output>

<result>65.94</result>