cylindrical water well has a circumference of 3.14m and a depth of 18m. The depth of water storage is (8/9) of the well. How many cubic meters of water does this well usually store?
一个圆柱形水井，它的井口周长是3.14m，井深18m，平时蓄水的深度是井深的(8/9)．这口井平时蓄水量是多少立方米？
<gadget id="calculator">3.14 / 3.14 / 2</gadget>
<output>0.5</output>

<gadget id="calculator">0.5 ** 2</gadget>
<output>0.25</output>

<gadget id="calculator">8 / 9</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">18 * (8/9)</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 0.25 * 16</gadget>
<output>12.56</output>

<result>12.56</result>