Reading Circle Graphs(pie charts)

Circle graphs, also called pie charts, are a type of graph used to represent a part to whole relationship.

· They are circular shaped graphs with the entire circle representing the whole.

· The circle is then split into parts, or sectors.

· Each sector represents a part of the whole.

· Each sector is proportional in size to the amount each sector represents, therefore it is easy to make generalizations and comparisons.

An example of a circle graph is given below.

Revenue Sources for the Federal Government

When reading this circle graph we look for the following pieces of information: the graph title, individual sectors and their relative sizes, and the sector labels (one for each sector). Let's take a closer look at each of these.

Graph Title--A graph title gives an overview of the information displayed in the graph. The title is given at the top of the graph. Sectors--Each sector represents one part of the whole. The size of each sector represents its fraction of the whole. Sector Labels--The label of each sector indicates the category of information it refers to, and may also give numeric data (often a percentage) so we know the size of each sector.

Let's use the circle graph given here as an example of how to get information from a circle graph. Looking at the elements of this graph we find:

· Graph Title --The title gives an overview of the information displayed in the graph.
The title of this graph is: