Creating a circular graph.

To create a circular graph, first you need a spreadsheet. Let's use Openoffice to do so.

Once it is open, first you have to introduce the data you want to represent:

 

Once it is done, select the titles and data to represent:

 

Now go to the option "insert graph":

 

Click and go to "Type of circular graph". You will see this:

 

Click "finish" and voilà!. As you see, it is very simple.