Volume is the amount of space that a three-dimensional object occupies;
and it is measured in cubic units. The most commonly used units of volume
are:
- mm3 - millimetres cubed
- cm3 - centimetres cubed
- m3 - metres cubed
The diagram of a cubic centimetre is shown below.
Dotted lines represent the edges of the cube that can not be seen when
we look at it from this angle. Each face of the cube is a square
centimetre, so the cube is said to be a cubic centimetre.
Finding Volume by Counting the Number of Cubes
If we can divide a three-dimensional object into small cubes of
side-length 1 cm as shown below, then the volume of the object can
be found by counting the number of cubes or cubic centimetres.
For example, the top layer of cubes in the rectangular box shown above
has two rows of 6 cubes. So, there are 12 cubes in the top layer.
Since there are 3 of these layers:
Example 1
Find the volume of each of the following solids by counting
cubes. Note that each small cube represents 1 cm3.
a.
b.
Solution:
Key Terms
volume, three-dimensional, cubic
units, millimetres cubed, centimetres
cubed, metres cubed |
