A tin bucket without cover is cylindrical, 30 cm high and 20 cm in diameter at the bottom. How many square centimeters of tin is used to make the bucket? The number obtained keeps the whole number~ Keep the whole number

A tin bucket without cover is cylindrical, 30 cm high and 20 cm in diameter at the bottom. How many square centimeters of tin is used to make the bucket? The number obtained keeps the whole number~ Keep the whole number

What's the bottom area
(20 △ 2) × (20 △ 2) × 3.14 = 314 square centimeter
What is the lateral area
20 × 3.14 × 50 = 3140 square centimeter
This bucket is made of iron
3140 + 314 = 3454 square cm ≈ 3500 square cm

A cylindrical open iron bucket, bottom diameter 20 cm, height 30 cm, do a pair of such buckets at least need how many square centimeters of iron?

Bottom area = 3.14 × (20 △ 2) &# 178; = 314 (square centimeter)
Side area = 3.14 × 20 × 30 = 1884 (cm2)
Required iron sheet area = (1884 + 314) × 2 = 4396 (cm2) = 43.96 (cm2)

In a cuboid bucket with a bottom area of 30dm, the depth of water is 3DM. Pour all the water into a cube container with an edge length of 5DM. How many decimeters is the water depth?

(30 × 3) △ 5 × 5, = 90 △ 25, = 3.6 (decimeter); a: the water depth is 3.6 decimeter