There is a rectangular iron sheet with a length of 18.84 decimeters and a width of 6.28 decimeters. Use it to make the side of a cylindrical bucket. To maximize the volume of the bucket, what is the area of the bottom of the bucket in square decimeters?
有一块长18.84分米，宽6.28分米的长方形铁皮，用它做一个圆柱形水桶的侧面，要使水桶的容积最大，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>