1. Volume of prisms and cylinders
Mathematics
Volume of prisms and cylinders

2. Lesson Objectives The aim of this powerpoint is to help you…
to learn and use the formula for finding the volume of a prism
to learn and use the formula for finding the volume of a cylinder

3. Dimensions
REMEMBER:
ADDING distances, areas or volumes together makes longer distances, bigger areas or bigger volumes
You have to MULTIPLY dimensions or distances together to get areas or volumes
As area is already 2D, you can find a volume by multiplying an area by another perpendicular dimension

4. Volume of Prisms
The volume of a prism is the area of its cross section (i.e. the shape that goes through the whole shape and gives the prism its name) multiplied by its height (or length)
V = Ah
To find the area of the cross section you will need to recall how to find the area of rectangles, triangles and rectilinear shapes.
Area
length
Area
height

5. Volume of Cylinders V V A h πr² h
A cylinder is a special type of prism – a circular prism.
You use the same formula but ‘A’ (the area) can be replaced by the formula for the area of a circle.
V = Ah  V = πr²h
radius
length
radius
height
V V
A h πr² h

6. Quick Practice Find the volume of this prism and cylinder… 3m 20cm²

7. Solutions… Volume = area of cross section × height
Volume = 20cm² × 6cm = 120cm³ 3m
20cm²
6cm 9m
Volume = (3.14 × 3m × 3m) × 9m = m³

8. What next?
Print out the notes called PAV5b-VolumeP. Read through them and make sure you answer any questions.
Work through the MyMaths lesson and its online homework called Volume of Prisms found at:
Now work through the MyMaths lesson and its online homework called Volume of Cylinders found at:
Save and complete the worksheet called VolP-S1.xlsx
Now prepare a revision sheet for your Geometry 2 assessment.