piece of round steel with a bottom radius of 10 cm is placed in a bucket with a bottom radius of 40 cm. The round steel sinks into the water, and the water level rises by 3 cm. Do you know how many centimeters the length of the round bar is?
在一个底面半径是40厘米的储水桶里，放入一段底面半径为10厘米的圆钢，圆钢全部沉到水中，这时水面升高了3厘米．你知道圆钢的长是多少厘米吗？
<gadget id="calculator">40 ** 2</gadget>
<output>1_600</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<gadget id="calculator">3 / 314</gadget>
<output>3/314 = around 0.009554</output>

<gadget id="calculator">3.14 * 1_600 * 1 * (3/314)</gadget>
<output>48</output>

<result>48</result>