1. Process a rectangular piece of wood with a length of 10cm, a width of 50cm and a height of 8cm into the largest cylinder. What is the surface area of the cylinder being machined?

Bottom radius: 8 ÷ 2 = 4 (cm)

The bottom area is 3.14× 4 2 = 50.24 (square centimeter).

Lateral area: 3. 14× 8× 50 = 1256 (square centimeter).

The surface area is: 50.24× 2+1256 =1356.48 (square centimeter).

2. The length of the roller is 1.4m and the diameter is 0.6m If the roller of this roller rotates 20 times per minute, how many meters can it press the road surface per hour? ?

3.14× 0.6×1.4× 20× 60 = 3165.12 (square meter)

3. A cylindrical milk powder can with a bottom radius of 6cm and a height of 15cm. How many centimeters does it take to cover the top and side of the milk powder can with trademark paper? Trademark paper? (Numbers are reserved as integers)

2× 3.14× 6×15 = 565.2 (square centimeter) ≈566 (square centimeter)

You can't use rounding here, you can only use one method.