There is a conical pile of soybeans, the circumference of the bottom surface is measured to be 15.7m, and the height is 1.8m. These soybeans are packed in a cylindrical granary, which just fills (1/3) of the granary. The height of the granary is 2.5m, how many square meters is its bottom area?
有一圆锥形黄豆堆，测得其底面周长为15.7m，高为1.8m，把这些黄豆装在一个圆柱形的粮仓中，正好装了这个粮仓的(1/3)，这个粮仓的高是2.5m，其底面积是多少平方米？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">15.7 / 3.14 / 2</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 ** 2</gadget>
<output>6.25</output>

<gadget id="calculator">1.8 / (1/3) / 2.5</gadget>
<output>2.16</output>

<gadget id="calculator">(1/3) * 3.14 * 6.25 * 2.16</gadget>
<output>14.13</output>

<result>14.13</result>