Star square has designed a cylindrical fountain with a bottom diameter of 40 meters and a depth of 1 meter. (1) if tiles are laid around and at the bottom of the fountain, how many square meters of tiles are needed? If every liter of water weighs 1kg, how many tons can the pool hold?

Star square has designed a cylindrical fountain with a bottom diameter of 40 meters and a depth of 1 meter. (1) if tiles are laid around and at the bottom of the fountain, how many square meters of tiles are needed? If every liter of water weighs 1kg, how many tons can the pool hold?

1 cubic meter of water weighs 1 ton, (1) 3.14 × 40 × 1 + 3.14 × (40 △ 2) 2, = 125.6 + 3.14 × 400, = 125.6 + 1256, = 1381.6, ≈ 1382 (square meters); answer: About 1382 square meters of ceramic tiles are needed. (2) 3.14 × (40 △ 2) 2 × 1 × 1, = 3.14 × 400 × 1 × 1, = 1256 (tons); answer: this pool can store 1256 tons of water