Surface Area of Solids

What is surface area?

Consider the cylinder shown in the picture. What two dimensional shapes combine to form the cylinder?

What is surface area?

Surface area is the material it takes to create the object.

Think of taking apart the object piece by piece and finding the area of each piece (shape). Add the areas of the shapes that form the object to get the surface area.

What shapes combine to form a cube?

A. circles

B. rectangles

C. Rectangles and squares

D. squares

How do we find area of a square?

A. A = lw

B. A = bh

C. A = s2

D. A = πr2

How many squares combine to form a cube?(Each one is called a “face.”)

A. 4

B. 6

C. 8

D. 10

What is the formula for the surface area of a cube?

A. SA = s2

B. SA = 6s2

C. SA = s3

D. SA = 6s3

Find the surface area of a cube, whose edge measures 5 cm.

150

0

What shapes combine to form a rectangular prism (box)?

What shapes combine to form a rectangular prism (box)?

A. Circles and squares

B. Squares

C. Squares and rectangles

D. Rectangles

What is the area of a rectangle?

A. A = s2

B. A = lw

C. A = πr2

D. A = 2l + 2w

How many rectangles form a rectangular prism?

6

0

Let’s look at a rectangular prism

Do you see the RED

face?

4 in.

7 in.

10 in.

What are the dimensions of this rectangle?10 in.

4 in.

Do you see another face that is just like the RED face?

Where is it located?

4 in.

7 in.

10 in.

Keep an eye on the next screen!

Yes, it’s on the back.

10 in.

4 in.

10 in.

4 in.

Now there are 2 rectangles

40 in2

40 in2 that each have an

area of 40 sq. in.

4 in.

7 in.

10 in.

Do you see the BLUE face?

What are the dimensions of this rectangle?

4 in.

7 in.

Do you see another face that is just like the BLUE face?

Where is it located?

4 in.

7 in.

10 in.

Yes, it’s on the left side.

4 in.

7 in.7 in.

4 in.

Now there are 2 rectanglesthat each have an area of 28 sq. in.

28 in2

28 in2

4 in.

7 in.

10 in.

Do you see the GREEN face?

What are the dimensions of this rectangle?

10 in.

7 in.

Do you see another face that is just like the GREEN face?

Where is it located?

4 in.

7 in.

10 in.

Yes, it’s on the bottom.

10 in.

7 in.

10 in.

7 in.

Now there are 2 rectanglesthat each have an area of 70 sq. in.

70 in2

70 in2

Now we just need to add all the areas of the sides together.

+ +

++ 70 in2

28 in2

40 in2

40 in2

28 in2

70 in2

The total Surface Area for this rectangular prism is

40 + 40 + 28 + 28 + 70 + 70 =

276 in2

Based on the previous example what is the formula for the surface area of a rectangular

prism?

A. SA = 6lw

B. SA = lw + wh + lh

C. SA = 2lw + 2wh + 2lh

D. SA = lwh

Use the formula to find the surface area of the rectangular prism with l = 6, w = 5 and b = 4.

148

0

What shapes combine to form a cylinder?

What shapes combine to form a cylinder?

What shapes combine to form a cylinder?

A. circles

B. rectangles

C. Circles and rectangle

D. Square and circles

What formula can be used to find the surface area of a cylinder?

A. SA = πr2

B. SA = 2πr2 + πdh

C. SA = πr2h

D. SA = 2πr2 + lw

Find the surface area of a cylinder whose radius is 5 and whose height is 8. (to the nearest tenth)

408.4

0

Basically, surface area can be found by

ADDING THE AREAS OF THE INDIVIDUAL SURFACES (SHAPES) THAT ARE COMBINED TO FORM THE OBJECT.