Example 3: Savitri had to make a model of a cylindrical kaleidoscope for her science project. She wanted to use chart paper to make the curved surface of the kaleidoscope. (see Fig 13.10). What would be the area of chart paper required by her, if she wanted to make a kaleidoscope of length 25 cm with a 3.5 cm radius?
Prerequisite
A closed cylinder has 3 surfaces:
- Curved or lateral surface
- Top
- Base
The formula to calculate the curved surface area and total surface area are quite simple to learn and derive.
Lateral or curved surface area of cylinder = 2πrh
r = radius, h = height (or length)
Total surface area of cylinder = 2πr ( r + h )
r = radius, h = height (or length)
It is recommended to understand the core concept of area, surface area and volume before we attempt any question based on these concepts.
Chapter 13 – Surface areas and Volumes
Concepts
- Area / Surface area / Volume – Introduction
- Surface Area of Cube and Cuboid
- Volume Of Cuboid and Cube
- Surface Area of Right Circular Cylinder
- Volume and capacity of Cylinder
- Right circular Cone
- Surface Area of Right circular Cone
- Volume of Cylinder vs Cone
- Litres and Cubic centimetre (cm³)
- Cubic meters to litres
