Question

39. If the height of a cylinder is equal to diameter of its base then its total surface area is a) 6ar? b) 81r? c) ar? d) Злr2​

Answer 1

Answer:

6πr²

Step-by-step explanation:

Total surface area of cylinder = 2πr (r+h)

here h= diameter = 2r

so total surface area will be = 2πr (r+2r)

= 2πr (3r)

= 6πr²

Answer 2

Answer :-

Option [A] → 6πr²

Step-by-step explanation :-

Given:

• Height of cylinder = Diameter of its base

To find:

Total Surface Area = ?

Solution:

Height of cylinder = Diameter of its base

➸ Height of cylinder = 2 × Radius of its base

⇢ h = 2r

We know that;

TSA of cylinder = 2πr (r + h)

Writing ‘h’ as 2r from the above equation,

TSA of cylinder = 2πr (r + 2r)

⇒ TSA of cylinder = 2πr (3r)

⇒ TSA of cylinder = 2 × 3 × π × r × r

⇒ TSA of cylinder = 6πr²

∴ TSA of cylinder = 6πr²