If the height of a cone is constant and the radius of the base is reduced (1/3), how much is the volume reduced
如果一个圆锥的高不变，底面半径减少(1/3)，则体积减少多少
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<result>5/9 = around 0.555556</result>