The side area of a cylinder is 12.56 square meters, the bottom radius is 4 decimeters, how many decimeters is its height?

The side area of a cylinder is 12.56 square meters, the bottom radius is 4 decimeters, how many decimeters is its height?

12.56 △ 3.14 × 4 × 2, = 12.56 △ 25.12, = 0.5 (decimeter); a: its height is 0.5 decimeter