The bottom of a bucket is circular and its circumference is 18.84 decimeters. What is the area of the bottom of this bucket?
一个水桶的底面是圆形，周长是18.84分米，这个水桶的底面积是多少平方分米？
<gadget id="calculator">18.84 / 3.14 / 2</gadget>
<output>3</output>

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

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

<result>28.26</result>