Question

The total surface area of a circular cylinder is 1320 sq. cm and it's radius is 10cm . Find the height of the cylinder....

Answer 1

Given :-

The The total Surface Area of cylinder = 1320 cm square

The radius is 10 cm

To be found :-

The height of the cylinder

 

The formula of curved surface area of cylinder is

= 2πr(r+h) unit square  

[ ∴ In which r is the radius and h is the height of the cylinder ]

⇒ 2πr(r+h) = 1320

⇒ $\bf 2 \times \frac{22}{7} \times10(10+h) = 1320$   [ as r = 10 cm ]

⇒ $\bf \frac{44}{7} \times10(10+h) = 1320$

⇒ $\bf \frac{440}{7} \: (10+h) = 1320$

⇒  $\bf (10+h) = 1320 \times \frac{7}{440}$

⇒ $\bf (10+h) = 21$

⇒ $\bf h = 21-10$

∴ h = 11 cm

Hence,

the height of the cylinder is 11 cm

Answer 2

Given :-

The The total Surface Area of cylinder = 1320 cm square

The radius is 10 cm

To be found :-

The height of the cylinder

 

The formula of curved surface area of cylinder is

= 2πr(r+h) unit square  

[ ∴ In which r is the radius and h is the height of the cylinder ]

⇒ 2πr(r+h)= 1320

⇒   [ as r = 10 cm ]

⇒

⇒

⇒  

⇒

⇒

∴ h = 11 cm

Hence,

the height of the cylinder is 11 cm