The diameter of the fountain in the cultural square is 40 meters, and there is a 4-meter-wide ring road around it. What is the area of this circular road in square meters?
文化广场的喷水池直径是40米，在它的外围有一条宽4米的环形路．这条环形路的面积是多少平方米？
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 + 4</gadget>
<output>24</output>

<gadget id="calculator">24 ** 2</gadget>
<output>576</output>

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

<gadget id="calculator">576 - 400</gadget>
<output>176</output>

<gadget id="calculator">3.14 * 176</gadget>
<output>552.64</output>

<result>552.64</result>