Question

Find the area of base and radius of a
cylinder if its curved surface area is
660 sq cm and height is 21 cm.
​

Answer 1

Answer :

The area of base is 78.6 cm² and radius is 5 cm.

Step-by-step explanation :

To Find,

• The area of base and radius of the cylinder

Solution,

Given that,

• Curved surface area = 660 cm²
• Height = 21 cm

Therefore,

As we know that,

Curved surface area = 2πrh,

Let the radius be r cm,

➯ 2 × 22/7 × r × 21 = 660

➯ 2 × 22 × r × 3 = 660

➯ 132 × r = 660

➯ r = 660 / 132

➯ r = 5

The radius of the cylinder is 5 cm.

Now, the area of base of cylinder is,

➯ 22/7 × ( 5 )²

➯ 22/7 × 5 × 5

➯ 22 × 5 × 5 / 7

➯ 550 / 7

➯ 78.6 cm²

Hence, the area of base is 78.6 cm².