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.