cylinder and a cone have the same base diameter. The height of the cone is three times that of the cylinder. The volume of the cone is 9 cubic meters. What is the volume of the cylinder?
一个圆柱和一个圆锥的底面直径相等，圆锥的高是圆柱的3倍，圆锥的体积是9立方米，圆柱的体积是多少立方米？
<result>9</result>