Surface Area: Rectangular Prism

Area of 2-D Shapes Review

Area of a Rectangle = Length x Width

Surface Area of Rectangular Prisms

Rectangular Prisms

Here's a rectangular prism with the dimensions:

length = 8cm

width = 4cm

height = 3cm

To find the surface area it might be helpful to draw the net. The rectangular prism has 6 faces.



Now you can see there are only 3 different sized rectangles.


Rectangle A = 3 x 8 = 24cm2

Rectangle B = 8 x 4 = 32cm2

Rectangle C = 3 x 4 = 12cm2


To find the surface area of the prism we need to total the area of all 6 faces:

24 + 24 + 32 + 32 + 12 + 12 = 136cm2


Surface area = 2 x area of Rectangle A

+ 2 x area of Rectangle B

+ 2 x area of Rectangle C


A cube is a type of rectangular prism with 6 congruent faces. If you find the surface area of one you'll have found the surface area of all six.

Then you'll need to add all six faces together to get the total surface area.