Question

9. The diameter of the base of a right circular
cylinder is 42 cm and the height is 10 cm.
Find its curved surface area.​

Answer 1

Answer:

Diameter of the base of the cylinder =42 cm 

∴ r = radius of the base of the cylinder =21 cm 

 h = height of the cylinder =10cm  

∴ curved surface area of the cylinder =  2πrh

          = 2×722×10cm2 

          = 2×22×3×10cm2=1320cm2

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

             = 2×722×21×(10+21)cm2

            = 2×22×3×31cm2=4092 cm2  

hope it's helpful for you guys

please mark me as brainliest

Answer 2

Given:-

• Base diameter of the base of right circular cylinder is 42 cm.
• Height of right circular cylinder is 10 cm.

To find:-

• Curved surface area of cylinder.

Solution:-

We know that,

Curved surface area of cylinder = 2πrh

In which,

• r is Radius of cylinder
• h is height of cylinder.

r = Radius = 42/2 = 21 cm.

h = height = 10 cm.

Put r and h in formula of Curved surface area of cylinder.

⇒ 2 × π × 21 × 10

⇒ 2 × 22/7 × 21 × 10

⇒ 2 × 22 × 3 × 10

⇒ 44 × 30

⇒ 1320

Therefore,

Curved surface area of right circular cylinder is 1320 cm².