Question

The total surface area of a cylinder whose radius is  `1/3` of its height is

Options

• `(9pi"h"^2)/8` sq.units

• 24πh² sq.units

• `(8pi"h"^2)/9` sq.units

• `(56pi"h"^2)/9` sq.units

Answer 1

`(8pi"h"^2)/9` sq.units

Explanation;

Hint:

Let the height of the cylinder be "h"

Radius of the cylinder = `1/3` h

T.S.A of the cylinder = 2πr(h + r)

= `2pi xx "h"/3 ("h" + "h"/3)`

= `2pi xx "h"/3 ((4"h")/3)`

= `(8pi"h"^2)/9` sq.units