Question

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

Answer 1

Curves surface area = 660 sq. cm

Height = 21 cm

∴ Curved surface area of cylinder = 2πrh

⇒ 660 = `2 xx 22/7 xx r xx 21`

⇒ 660 = 2 × 22 × r × 3

⇒ 660 = 132 r

⇒ r = `660/132` = 5 cm

∴ Area of base = π r²

= `22/7 xx 5 xx 5`

= 78.57 sq. cm

∴The radius of the cylinder is 5 cm and the area of its base is 78.57 sq.cm.