Question

Heya User,

Answer the Question :-

Find the total surface of a hollow cylinder open at ends, if the length is 12 cm, the external diameter 10 cm and thickness 2 cm.

Answer 1

Answer:

$\huge\boxed{\boxed{\blue{75.36\:cm^2}}}$

Step-by-step explanation:

Given information :

Length of the cylinder = 12 cm .

External diameter of the cylinder = 10 cm .

Thickness = 2 cm .

Internal diameter = external diameter - thickness

⇒ Internal diameter = 10 cm - 2 cm ⇒ 8 cm

Internal radius ( r ) = 8 cm / 2

⇒ r = 4 cm .

External radius = R

R = 10 cm / 2

⇒ R = 5 cm .

Height =  12 cm ( given )

Volume of cylinder = 2 π h ( R - r )

⇒ 2 × 3.14 × 12 ( 5 - 4 )

⇒ 2 × 3.14 × 12 × 1

⇒ 6.28 × 12

⇒ 75.36

Hence the total surface area is 75.36 cm² .

Answer 2

Solution :-

Length of the cylinder = 12 cm

External diameter of the cylinder = 10 cm

Thickness = 2 cm

Internal diameter = external diameter - thickness

⇒ Internal diameter = 10 cm - 2 cm

⇒ Internal diameter = 8 cm

Internal radius (r) = 8 cm / 2

⇒ r = 4 cm

External radius (R) = 10 cm / 2

⇒ R = 5 cm

Height = 12 cm

Volume of cylinder = 2πh( R - r )

⇒ 2 × 3.14 × 12 ( 5 - 4 )

⇒ 2 × 3.14 × 12 × 1

⇒ 6.28 × 12

⇒ 75.36

Hence the total surface area is 75.36 cm².