Question

The given figure shows a solid cylinder and a solid cone on it according to the given measurement, the total surface area of the solid in terms of π and r is:

Options

• 4πr²

• 5πr²

• 6πr²

• 7πr²

Answer 1

5πr²

Explanation:

From figure,

Total surface area of solid = Curved surface area of cylinder + Curved surface area of cone + Area of cross-section

= 2πrh + πrl + πr²

= 2πr.r + πr.2r + πr²

= 2πr² + 2πr² + πr²

= 5πr²