A cylindrical measuring cup, measured from the inside, with a bottom diameter of 8 cm, is now filled with water, and a rectangular iron block is put into the water, and it is submerged by the water. As a result, the water level rises by 5 cm, what is the volume of the iron block?
一只圆柱形的量杯，从里面量，底面直径8厘米，现装有水，把一块长方形的铁块放入水中，被水淹没．结果水面上升5厘米，求铁块的体积？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

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

<gadget id="calculator">3.14 * 16 * 5</gadget>
<output>251.2</output>

<result>251.2</result>