A cylindrical tin bucket without a cover, 30 cm high, with a bottom radius of 10 cm. How many square decimeters of tin is used to make the bucket at least? Remember that units are different

A cylindrical tin bucket without a cover, 30 cm high, with a bottom radius of 10 cm. How many square decimeters of tin is used to make the bucket at least? Remember that units are different


1 * 1 * 3.14 + (1 + 1) * 3 * 3.14 = 21.98 (square decimeter)