find the total surface area of cylinder whose height is 7 cm and radius is 7 cm.
Answers
Given:
- Height of cylinder = 7 cm
- Radius of cylinder = 7 cm
To find:
Total Surface area of cylinder = ?
Solution:
In this question, let h be the height of cylinder and r be the Radius of cylinder.
Substitute the known values in the formula of TSA of cylinder and we get the value of TSA of cylinder.
Let's solve it.
TSA of cylinder = 2πr (r + h)
→ TSA of cylinder = 2 × 22/7 × 7 × (7 + 7)
→ TSA of cylinder = 14 × 22/7 × 14
→ TSA of cylinder = (14 × 22 × 14) ÷ 7
→ TSA of cylinder = 616 cm²
∴ TSA of cylinder = 616 cm²
KNOW MORE:
How formula of TSA of cylinder is 2πr (r + h)?
Let's visualise.
There are 2 circles in a cylinder. Each has an area of πr². So, 2πr².
When we unfold the remaining part of cylinder, we get a rectangle with length 2πr and Height h.
So the Area of rectangle = l × b = 2πrh
Hence the total area would be:
2πr² + 2πrh
= 2πr (r + h)