Curved surface area of cylinder = Area of rectangle = length x breadth
= circumference of the base of the cylinder height of the cylinder
= 2πr x h = 2πrh
The upper and the lower surface of the closed cylinder is circular
∴ total surface area of closed cylinder = curved surface area + area of upper surface + area of lower surface
∴ total surface area = curved surface area + 2 x area of circular faces
= 2πrh + 2πr2 = 2πr(h + r)
In each example given below, radius of base of a cylinder and its height are given. Then find the curved surface area and total surface area.
(1) r = 7 cm, h = 10 cm
(2) r = 1.4 cm, h = 2.1 cm
(3) r = 2.5 cm, h = 7 cm
(4) r = 70 cm, h = 1.4 cm
(5) r = 4.2 cm, h = 14 cm
Find the total surface area of a closed cylindrical drum if its diameter is 50 cm and height is 45 cm. (π = 3.14)
Find the area of base and radius of a cylinder if its curved surface area is 660 sqcm and height is 21 cm.