Question

Find the area of base and radius of a cylinder if its curved surface area is 660 sqcm and hight is 21 cm​

Answer 1

h = 21 cm

CSA of cylinder = 660 sq. cm

=> 2πrh = 660

=> 2× 22/7 × r × 21 = 660

=> 132 r = 660

=> r = 660/132

=> r = 5cm

ar. of base = πr² = 22/7 × 5× 5 = 78.56 cm²

Answer 2

Answer:

Given,

Curved surface area = 660 sq.cm, and height = 21 cm

Required to find: area of base and radius of a cylinder

We know that,

Curved surface area of cylinder = 2πrh

⇒ 660 = 2 x (22/7) x r x 21

660 = 2 x 22 x r x 3

6602 × 22 × 3 = r

6602 × 66 = r

r = 5 cm

Now,

Area of a base of the cylinder = πr²

= (22/7) x 5 x 5

= 5507

= 78.57 sq.cm

Thus, the radius of the cylinder is 5 cm and the area of its base is 78.57 sq.cm.