The pie chart is used to graph parts of a whole, the total of our numbers must be 100%. The pie chart is, unfortunately, one of the most use charts, you see them often in newspapers and magazines. You shouldn't use them at all, in my opinion, they are hard to read and not that useful.

How to build

1. Select the cell range that contains the values you want to chart.
   
2. Go to tab "Insert" on the ribbon.
3. Press with left mouse button on the "Pie or Doughnut Chart" button.
4. Press with left mouse button on the "Pie Chart" button.
   

Improve the pie chart

There are a few things we can do to make the pie chart a little easier to read.

Add data labels

1. Press with right mouse button on on chart to open a menu.
2. Press with mouse on "Add Data Labels".
   
3. Select the data labels and change the font size.

Sort values

1. Press with right mouse button on on one of the chart data source values.
2. Press with left mouse button on "Sort" then press with left mouse button on "Sort Largest to Smallest".
   

The chart pies are now sorted from largest to smallest and the data labels show how large they are.