cylindrical fountain has an inner diameter of 8m and can hold water at most 25.12m**3. How deep is the pool?
一圆柱形喷水池，池内直径是8m，最多能装水25.12m**3，水池有多少米深？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<gadget id="calculator">25.12 / 50.24</gadget>
<output>0.5</output>

<result>0.5</result>