The radius of the bottom of a cylindrical bucket is 20 cm. When a piece of iron (completely submerged in water) is taken out of the bucket, the water level in the bucket drops by 1 cm. What is the volume of the piece of iron in cubic centimeters?
一个圆柱形水桶的底面半径是20厘米，把一块铁块(完全浸没在水中)从水桶中取出后，水桶里水面下降了1厘米，这块铁块的体积是多少立方厘米？
<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400 * 1</gadget>
<output>1_256</output>

<result>1_256</result>