Surface area of a cylinder
The shape can be thought of as a circular prism. Cylinder could be closed or open. Surface areas for a cylinder is investigated.
To find surface area of a cylinder
Prerequisites/Instructions, prior preparations, if any
- The cylinder is a 3 dimensional solid having curved lateral surface with two circular surfaces on either sides.
- Basics of circle and rectangle.
- Formula to find the area of a circle and a rectangle.
Materials/ Resources needed
Digital: Laptop, internet link, projector and a pointer.
Download this geogebra file from this link.
Process (How to do the activity)
- The teacher can initially discuss about cylinder as a shape and explain its parts.
- She can then talk about what area means.
- Discuss regarding surfaces to be covered in deriving the formula for surface area of the cylinder.
- Project the video and discuss.
- Can youn identify the shapes of the open cylinder?
- What is the radius of the circle ?
- What is the formula to find the circumference of the circle.
- Into what shape does the curved surface of the cylinder opens ?
- What are the measures of height and breadth of the rectangle?
- What is the formula to find the area of the rectangle ?
- Can you explain the conversion of circumference of the circle into the length of the rectangle ?
- Question Corner:
- What is the difference between lateral and total surface area ?
- What are the formulae for lateral surface area and total surface area ?
- Name a few situations wherin one may have to find only the lateral surface area of the cylindrical object ?