The base of a sculpture is circular with a radius of 15m, surrounded by a circular lawn with a width of 5m, what is the area of the lawn in square meters?
一座雕塑的基座是圆形的，半径为15m，在它的周围是5m宽的环形草坪，草坪的面积是多少平方米？
<gadget id="calculator">15 + 5</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">15 ** 2</gadget>
<output>225</output>

<gadget id="calculator">400 - 225</gadget>
<output>175</output>

<gadget id="calculator">3.14 * 175</gadget>
<output>549.5</output>

<result>549.5</result>