The lateral area of a cylinder is the area of the curved surface of the cylinder. If we unfold the lateral surface
of the cylinder, we get a rectangle. The measure of the area of the rectangle is the lateral area of the
cylinder. The lateral area of the cylinder can be found by using the formula
L.A. = pi * r2 * h
where r is the radius of the cylinder,
h is the height of the cylinder
Example 1: What is the lateral area of the cylinder with radius equal to 6 cm and height equal to 14 cm.
Solution: Lateral area of the cylinder can be found using the formula,
L.A. = pi * r2 * h = 22 / 7 * 62 * 14
L.A. = 11088 / 7 = 1584
Thus the lateral area of the given cylinder is 1584 square centimeters.
Example 2: The lateral surface of a barrel in the shape of a cylinder is to be painted. The height of the
barrel is 7 feet and radius is 2 feet. What is the cost of painting if cost per square foot is $1.5.
Solution: The lateral area of the cylinder can be found using the formula,
L.A. = pi * r2 * h = 22/7 * 22 * 7 = 616 / 7 = 88 square feet
Cost of painting one square foot of the area = $ 1.5
Cost of painting the lateral surface of the cylinder = 88 * 1.5 = $132.