Always remember to add a descriptive title to your chart.
To be sure that anyone, whether they know the data or not, can understand what is presented in your chart, you must give it a title. Try to describe your chart in a few simple words. If your audience would appreciate some humor, you can choose a funny or clever title. Every organization has its own policy for what's acceptable. Whatever you choose, the purpose of the chart should be clear from the title.
For pie charts – and indeed for all charts – titles are usually placed in the top left corner. Depending on how you will use your chart, you may want to include information about the measures and variables used.