A master worker forges a cone from a cylindrical billet with a length of 6 cm. It is known that the area of the bottom of the cone is twice the area of the bottom of the billet. What is the height of the cone in cm?
工人师傅用长6cm的圆柱形钢坯锻造成圆锥，已知圆锥的底面积是钢坯底面积的2倍，圆锥的高是多少cm．
<gadget id="calculator">3 / 1</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

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

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<result>9</result>