A cylinder and a cone have the same volume and the same circumference of the bottom surface. If the height of the cone is reduced by 9 centimeters, it will be as tall as the cylinder. What is the height of the cylinder in centimeters?
一个圆柱和圆锥，它们体积相等，底面周长也相等，如果圆锥的高减少9厘米，就和圆柱同样高了；圆柱的高是多少厘米．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>