Use a 20 cm long, 12 cm wide rectangular paper to form a cylinder. The volume of the cylinder is () cubic cm at most

Use a 20 cm long, 12 cm wide rectangular paper to form a cylinder. The volume of the cylinder is () cubic cm at most

When the perimeter of the bottom surface is 20 cm and the height is 12 cm, the volume is the largest
So:
Radius = 20 △ 2 × π = 10 parts of π
Volume = π× (10 / π) & # 178; × 12 = 1200 / π cubic centimeter