Answer:
The surface area is the total area of all the faces.
For a cuboid, all these faces will be rectangular.
Example:
Find the surface area of a 2 x 4 x 5 cm cuboid.
The area of the faces will be:
2 x 4 = 8 cm2
2 x 5 = 10 cm2
4 x 5 =20 cm2
Adding these up give an area of 38 cm2.
However we now need to multiply our answer by 2 as there are exactly two of each face.
So our final answer is 38 x 2 = 76 cm2.