The height and base radius of the cone are both (1/3) of the cylinder, and the volume of the cone is that of the cylinder ((())/(())).
圆锥体的高和底面半径都是圆柱体的(1/3)，圆锥体的体积是圆柱体的((())/(()))．
<gadget id="calculator">1 / 81</gadget>
<output>1/81 = around 0.012346</output>

<result>1/81 = around 0.012346</result>