# Lateral Surface Area of a Cuboid

Here we will learn how to solve the application problems on lateral surface area of a cuboid using the formula.

Formula for finding the lateral surface area of a cuboid

Area of a Rooms is example of cuboids.

Are of the four walls of a room = sum of the four vertical (or lateral) faces

= 2(l + b)h

Where l = Length, b = breadth and h = height.

Therefore, lateral surface area of a cuboid = 2(l + b)h

Problems on Lateral Surface Area of a Cuboid:

The dimensions of a cubical room are 8.6 m × 5.4 m × 4 m. The room has two doors each measuring 2 m by 1 m and four windows each measuring 1 m by 1 m. What will be the cost of plastering the four walls and the ceiling at RS 65 per m2?

Solution:

The total area of the four walls

= Lateral surface area of the cuboid

= 2(l + b)h

= 2(86 + 5.4) × 4 m2

= 112 m2.

The area of the ceiling = l × b

= 8.6 × 5.4 m2

= 46.44 m2

The sum of the areas of the two doors and the four windows

= 2(2 × 1) m2 + 4(1 × 1) m2

= 8 m2

Therefore, the total area to be plastered = (112 + 46.44 - 8) m2

= 150.44 m2

Therefore, the cost of plastering = 150.44 × Rs. 65

= Rs. 9778.60.