A cylinder iron block with a bottom area of 6.28 square decimeters and a height of 9 decimeters is melted and cast into a cone with a bottom area of 12.56 square decimeters. What is the height of the cone?

A cylinder iron block with a bottom area of 6.28 square decimeters and a height of 9 decimeters is melted and cast into a cone with a bottom area of 12.56 square decimeters. What is the height of the cone?

6.28 × 9 × 3 ﹣ 12.56, = 56.52 × 3 ﹣ 12.56, = 169.56 ﹣ 12.56, = 13.5 (decimeter); answer: the height of the cone is 13.5 decimeter