Prisms

1
Prisms
06 November 2009
Here are two prisms
Its easy
This sounds difficult
Objective Calculate the volume of prisms
Vol. Area End x Length
2
Which of these shapes are prisms? Describe a
prism. A prism has
3
Volume Area of the End x The Length
4
How to find the volume of a cuboid
Volume Base x Width x Height
V B x H x W V 4 x 10 x 2 V 80 cm3
10 cm
2 cm
4 cm
This cuboid has Base 4 cm Height 10
cm Width 2 cm
5
First fond the area of the end. Its a trapezium
so A (8 4) 2 x 10 A 12 2 x 10 A 6
x 10 A 60 cm2 Now multiply this by the length
to get the volume V 60 x 15 V 900 cm3
4
15
10
8
6
First fond the area of the end. Its a circle
so A ?r2 A 3.14 x 5 x 5 A 78.5 cm2 Now
multiply this by the length to get the volume V
78.5 60 x 7 V 549.5 cm3
Radius 5 cm
Height 7 cm
7
Volume Area x Length Area Volume
Length Length Volume Area
V
A
L

• 1000 15 66.7 cm2
• A pr2
• ? r v(A p)
• ? r v(66.7 3.14)
• ? r 4.6 ? dia. 9.2

A tin of soup has a volume of 1000 cm3 and a
height of 15 cm. What is a) the area of its
end b) the diameter?
8
1. Here is a table that gives the dimensions of
six prisms. Copy and complete the table.
2. This tent is an approximate triangular prism.
What is its volume if it is 1.2 metres high, 1.5
metres wide and 2.4 metres long?
3. Calculate the volume of this tin if it has a
radius of 8 cm and a height of 20 cm
9
1. Here is a table that gives the dimensions of
six prisms. Copy and complete the table.
2. V Area x Length V 1.2 x 1.5 2 x 2.4
V 2.16 metres3

• V Area x Length
• V pr2 x L
• V 3.14 x 82 x 20
• V 4019.2 cm2
• V 4019.2 millilitres