SURFACE AREA OF CUBOID -
Surface are of a cuboid is the sum of the areas of all its six rectangular faces.
The adjoining diagram shows a cuboid with, length = l units
breadth = b units,
and, height = h units,
The six faces of the cuboid are shown below -
1) There are two faces (top & bottom) each with area = l X b sq.units
2) There are two faces (front & back) each with area = l X h sq.units
3) There are two faces (right & left) each with area = b X h sq.units
The surface area of the cuboid
= sum of areas of all six faces
= 2 (lb + lh + bh) sq.units
Example.1) Let's say you have a rectangular box (cuboid) with the following dimensions:
Ans.)
To find the surface area of this cuboid, you would use the formula:
Surface Area = 2(lw + lh + wh)
Surface Area = 2 {(8 cm X 5 cm) + (8 cm X 3 cm) + (5 cm X 3 cm)}
Surface Area = 2(40 cm² + 24 cm² + 15 cm²)
Surface Area = 2 (79 cm²)
Surface Area = 158 cm²
So, the surface area of this cuboid is 158 square centimeters. (Ans.)
Example.2) Suppose you have a rectangular storage container with the following measurements:
Ans.)
To calculate the surface area, use the formula:
Surface Area = 2(lw + lh + wh)
Surface Area = 2 {(12 in X 6 in) + (12 in X 4 in) + (6 in X 4 in)}
Surface Area = 2 (72 in² + 48 in² + 24 in²)
Surface Area = 2 (144 in²)
Surface Area = 288 in²
The surface area of this rectangular storage container is 288 square inches. (Ans.)