The diameter of a circular garden on the square is 20 meters. A path with a width of 2 meters is paved along the outside of the garden. What is the area of the path in square meters?
广场上一个圆形花园的直径是20米，沿花园外侧铺一条2米宽的小路，求小路的面积是多少平方米？
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<gadget id="calculator">12 ** 2</gadget>
<output>144</output>

<gadget id="calculator">3.14 * 144</gadget>
<output>452.16</output>

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

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<gadget id="calculator">452.16 - 314</gadget>
<output>138.16</output>

<result>138.16</result>