A cylindrical measuring cylinder with a bottom radius of 4 cm. When an iron block is put into the measuring cylinder, the water level rises by 3 cm. Find the volume of the iron block.
一个底面半径4厘米的圆柱形量筒，把一个铁块放入量筒后水面上升了3厘米，求这个铁块的体积．
<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16 * 3</gadget>
<output>150.72</output>

<result>150.72</result>