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 = 70 cm, h = 1.4 cm

Answer 1

We know that,

Curved surface area = 2πrh

Total surface area = 2πr(h + r)

Here, r = 70 cm, h = 1.4 cm

Curved surface area of a cylinder = 2πrh

= `2 xx 22/7 xx 70 xx 1.4`

= `44 xx 14`

= 616 sq.cm.

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

= `2 xx 22/7 xx 70(1.4 + 70)`

= `440 xx 71.4`

= 31,416 sq.cm.