A cylindrical glass container is filled with water. Put a piece of round steel with a cross-sectional radius of 5 cm into the water, and the water level rises by 9 cm; let the round steel in the water protrude 8 cm long, and the water in the container is now What is the volume of this piece of round steel if it falls 4 cm?
一个圆柱形玻璃容器内盛有水，把一段横截面半径是5厘米的圆钢全部放入水里，水面上升9厘米；再让水中的圆钢露出8厘米长，这时容器内的水就下降4厘米，这段圆钢的体积是多少？
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">3.14 * 25 * 2 * 9</gadget>
<output>1_413</output>

<result>1_413</result>