Put a conical iron block into a cylindrical container and submerge it completely. The water level rises by 3 cm. The circumference of the bottom surface of the cylinder is 12.56 cm. Find the volume of the cone.
把圆锥形铁块放入圆柱形容器中，完全侵没，水面上升3厘米，圆柱的底面周长是12.56厘米，求圆锥的体积．
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4 * 3</gadget>
<output>37.68</output>

<result>37.68</result>