Surface Area

Surface Area (Cube and Rectangular Prism)

by Mr. Winters

Objectives

• to provide you with both a definition and understanding of Surface Area

• to demonstrate how to find the surface area of certain 3-D objects

What is Surface Area?

The Surface area is the total area of all the surfaces of a 3-D object. Examples are: cubes, triangular prisms, & rectangular prisms.

REMEMBER since we are dealing with 3-D objects, your unit measurements must be CUBED!!!

Multiple Choice

What is the definition of Surface area?

• The total area of all the surfaces of a 2-D object?

• The total area of all the surfaces of a 3-D object?

• The top area of an object?

Surface area of a Cube

Remember a cube is a 3-D object that has 6 equal sides.

To find the surface area of a Cube, we simply have to take the total (sum) of each side's surface area.

The formula is SA = 6s² , where s equals one side

Multiple Choice

What is the surface area of this cube?

• 150ft³

• 25ft³

• 150ft²

Multiple Choice

What is the surface area of this cube?

• 54 cm²

• 36 cm³

• 54 cm³

Surface area of a Rectangular Prism

A rectangular prism is a 3-D object that has 56 sides. Those sides are 4 rectangles and 2 squares.

To find the total surface area, all we have to do is add each side's surface area.

Formula: SA = 2lw + 2wh + 2lh

Multiple Choice

What is this object's surface area?

• 144 in³

• 164 in³

• 144 in²

Multiple Choice

What is the surface area of this object?

• 148 cm³

• 188 cm³

• 148 cm²