Surface Area Geometry Volume

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.

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

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.

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

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

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

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

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

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

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.

2) Divide the net into its different faces

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

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

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.

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

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

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

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

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