The surface area of a rectangular prism is is the area of the six rectangles that cover it.
If we break the rectangular prism into its parts we are going to have 2 bases and 4 lateral faces (rectangles) which make up the lateal area.
It is pretty easy to calculate their areas and then add them up.
What is the surface area?
A rectangular prism has 3 pairs of identical faces. Each face is a rectangle.
Find the area of the faces in each pair.
Now add the areas of the 6 faces.
Surface area = 
24 + 24 + 54 + 54 + 36 + 36

= 
228 
The surface area of the rectangular prism is 228 square centimeters