Question

In the example given below, the radius of the base of a cylinder and its height is given. Then find the curved surface area and total surface area.

r = 2.5 cm, h = 7 cm

Answer 1

We know that,

Curved surface area = 2πrh

Total surface area = 2πr(h + r)

Here, r = 2.5 cm, h = 7 cm

Curved surface area of a cylinder = 2πrh

= `2 xx 22/7 xx 2.5 xx 7`

= `44 xx 2.5`

= 110 sq.cm.

Total surface area of a cylinder = 2πr(h + r)

= `2 xx 22/7 xx 2.5(7 + 2.5)`

= `110/7 xx 9.5`

= `1045/7 = 149.285`

≈ 149.29 sq. cm.