There are five same cylindrical columns in the hall. The perimeter of the bottom surface of each column is 3.14 meters and the height is 4 meters. To paint these columns, 0.5 kg per square meter, how many kg of paint do you need?

There are five same cylindrical columns in the hall. The perimeter of the bottom surface of each column is 3.14 meters and the height is 4 meters. To paint these columns, 0.5 kg per square meter, how many kg of paint do you need?

Surface area (i.e. paint area to be brushed) = 3.14 * 4 = 12.56
Total requirement: 5 * surface area * 0.5 = 31.4kg

There are eight same cylindrical wooden columns in the hall, each of which is 5 meters high and the perimeter of the bottom is 3.2 meters?

The side area of each column: 3.2 × 5 = 16 (square meters), the surface area of 8 columns painted: 16 × 8 = 128 (square meters), the kilogram of paint to be used: 128 △ 4.5 ≈ 28.4 (kilogram); answer: 28.4 kilogram of paint is needed to paint these wooden columns

There are eight cylindrical wooden piles in the hall to be painted. The perimeter of the bottom surface of the wooden piles is 2.5 meters and the height is 4.2 meters. One kilogram of paint can be painted for 6 square meters. How much paint does it take to paint these wooden piles?

The side area of each column: 2.5 × 4.2 = 10.5 (square meters), the surface area of 8 columns painted: 10.5 × 8 = 84 (square meters), the kilogram of paint to be used: 84 △ 6 = 14 (kilogram); a: a total of 14 kilogram of paint to be used