 4 Ijesha Close, Ilupeju, Lagos
+2347 086 296 002

#### Cylinder - Area and Volume

• A cylinder of height h, and circular base of radius r has a curved surface area of 2πrh. If it is closed, it also has two circular end faces, each of area πr². Therefore, the total surface area of a closed cylinder is 2πrh + 2πr².
• The surface area of an open-ended cylinder container will be 2πrh + 2πr².
• In general, the volume of a prism = Area of end face × Distance between the end faces. Therefore, the volume of a cylinder with radius r, and height h = πr²h.
###### Examples
1. A cylindrical cup has a base of radius 7 cm and a height of 10 cm. Taking the value of π to be 22/7, calculate :
1. its curved surface area.
• the area of the curved surface of a cylinder of radius r and height h is 2πrh.
• The curved surface area of the cup = 2 × 22/7 × 7 × 10
• ∴ The curved surface area of the cup = 440 cm²
2. the area of its circular base.
• the area of the circular base of the cup = 22/7 × 7 × 7
• ∴ The area of its circular base = 154 cm²
2. How many liters can be held by a cylindrical can 14 cm in diameter and 20 cm high?
• Volume of can = πr²h
•                            = 22/7 × 7 × 7 × 20
•                            = 3080 cm³
• 1 liter = 1000 cm³
• ∴ Capacity of the can = 3.08 liters.
• The can holds about 3 liters.
Minimum 4 characters