1. Surface Area
Geometry
Volume

2. Geometry Surface Area Volume The amount of space a 3D shape takes up.
The total area of all the faces that make up a 3D shape
The amount of space a 3D shape takes up.

3. Surface Area Remember 3D shapes are a collection of 2D shapes
Each 2D shape is a face on a 3D shape

4. What is Surface Area?
Surface Area is the total area of all the faces that make up a 3D shape
Think of it like finding the area of each side of a dice.
That is the dice’s surface area.

5. How do you find the surface area of a 3D shape?
What is Surface Area?
How do you find the surface area of a 3D shape?
First you need to understand that all 3D shapes are a collection of 2D shapes 2 2 =
This is called a NET
It is a way of showing the 2D shapes that create a 3D shape

6. How do you find the surface area of a 3D shape?
Split up the shape into a NET. 2

7. How do you find the surface area of a 3D shape?
2) Divide the NET into its different faces

8. How do you find the surface area of a 3D shape?
3) Calculate the area of each face 2m
4m2

9. How do you find the surface area of a 3D shape?
4) Add the area of each face.
+ 4m2
+ 4m2 =
4m2
4m2
24m2

10. Example What is the surface area of this triangular prism?
8 in
Here are your steps
Split the shape into its net.
Divide the net into its different faces.
Calculate the area of each face.
Add the area of each face.
15 in
4 in
10in

11. Example What is the surface area of this triangular prism?
Split the shape into its net.
8 in
15 in
10in
4 in
Hint: it is always a good idea to count the number of shapes to make sure you didn’t forget any.

12. 2) Divide the net into its different faces

13. 3) Calculate the area of each face
8 in
15 in
10in
4 in
8 in
8(4) 2
= 16
4 in
4 in
8 in
10in
4 x 15 = 60
8 x 15 =120
10 x 15 = 150
15 in
8 in
8(4) 2
4 in
= 16

14. 4) Add the area of each face
60 in2
120 in2
150 in2
16 in2
+ 16 in2
362 in2
8 in
8(4) 2
= 16
4 in
4 in
8 in
10in
4 x 15 = 60
8 x 15 =120
10 x 15 = 150
15 in
8 in
8(4) 2
4 in
= 16

15. Surface Area Split the shape into its net.
Divide the net into its different faces.
Calculate the area of each face.
Add the area of each face.

16. Don’t click until you are finished The answer is on the next slide
You Try
What is the area of this rectangular prism
Don’t click until you are finished
The answer is on the next slide
2 cm
4 cm
5 cm

17. Answer 1) Split the shape into its NET 2 cm 4 cm 5 cm Front Top Back
Bottom
Side

18. Answer 2) Divide the NET into different faces 2 cm 4 cm 5 cm Front
Top
4 cm
5 cm
2 cm
Back
2 cm
2 cm
Side
5 cm
Side
4 cm
4 cm
Bottom
4 cm
5 cm

19. Answer 3) Calculate the area of each face 2 cm 4 cm 5 cm 10cm2 2 cm

20. Answer 76cm2 4) Add the area of each face 10cm2 20cm2 8cm2 + 8cm2 2 cm