Dig a cylindrical water tank, so that its volume is 188.4 cubic meters, the radius of the pool is 3 meters, how many meters should be dug deep?
挖一个圆柱形蓄水池，要使它的容积是188.4立方米，水池的半径是3米，应挖多少米深？
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

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

<gadget id="calculator">188.4 / 28.26</gadget>
<output>6.666667</output>

<result>6.666667</result>