Surface Area of Prisms

Volume of prisms

by Sophie Bark

​Prisms recap

​Which of the following is not a prism?

​a)

​b)

​c)

​d)

​e)

Multiple Choice

Select the correct definition for a prism

• A 3D shape that has straight edges

• A 3D shape that has at least one pair of opposite identical faces

• A 3D shape that has squares for faces

• A 3D shape that has two triangles on each

​Finding the surface area of a prism

​To find the surface area we have to draw the net of the prism...

​

​What would the net of this prism look like?

​Finding the surface area of a prism

​To find the surface area we have to draw the net of the prism...

​

​What would the net of this prism look like?

Multiple Choice

What is the surface area of the prism?

• $$30\ cm^2$$  

• $$24\ cm^2$$  

• $$16\ cm^2$$  

• $$38\ cm^2$$  

​What is the volume of a prism?

​Surface area is the area of the outside faces of a 3D shape

​

​What does "volume" of a prism mean?

​What is the volume of a prism?

​Surface area is the area of the outside faces of a 3D shape

​

​What does "volume" of a prism mean?

​The volume of a prism is the "space" inside a 3D shape

​What is the volume of a prism?

​Surface area is the area of the outside faces of a 3D shape

​

​What does "volume" of a prism mean?

​The volume of a prism is the "space" inside a 3D shape

​The volume is similar to the amount of liquid that could fit in the shape, this is known as the capacity (ml, litres etc)

​How do we calculate the volume?

​Step 1 - identify and shade the cross section of the prism

​

​Step 2 - calculate the area of the cross section

​

Step 3 - multiply the area of the cross section by the length

​What do we measure volume in ?

​How do we calculate the volume?

​Step 1 - identify and shade the cross section of the prism

​

​Step 2 - calculate the area of the cross section

​

Step 3 - multiply the area of the cross section by the length

​What do we measure volume in ?

Multiple Choice

What is the volume of this rectangular prism?

• $$12\ cm^3$$  

• $$14\ cm^3$$  

• $$84\ cm^3$$  

• $$49\ cm^3$$  

​Formula for volume

​We can write a rule for finding the volume of a prism:

​Now let's try on another shape, find the volume of this triangular prism

​

Remember the formula for area of a triangle is:

Multiple Choice

Find the volume of the triangular prism

• $$288\ cm^3$$  

• $$144\ cm^3$$  

• $$96\ cm^3$$  

• $$23\ cm^3$$  

Multiple Choice

Find the volume of the cuboid

• $$72\ cm^3$$  

• $$18\ cm^3$$  

• $$24\ cm^3$$  

• $$13\ cm^3$$  

Multiple Choice

Find the volume of the triangular prism

• $$52.5\ cm^3$$  

• $$70\ cm^3$$  

• $$42\ cm^3$$  

• $$19\ cm^3$$  

Poll

How confident do you feel with finding the volume of prisms?

• I feel confident finding both volume of rectangular and triangular prisms

• I can find the volume of rectangular prisms but triangles are tricky

• It's hard, but I am beginning to understand

• I really need some help