A cone and a cylinder with the same base area, their volume ratio is 1:2, the height of the cone is 9 cm, what is the height of the cylinder in cm.
底面积相等的圆锥和圆柱，它们的体积比是1：2，圆锥的高是9cm，圆柱的高是多少cm．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/3) * 9</gadget>
<output>6</output>

<result>6</result>