These fractions would be out of 360°, the number of degrees in a full turn. A pie chart may include the percentages of what each sector represents. These can also be used to work out proportions ...

“Imagine a pie chart that shows Visuals at 42 percent, Numbers at 36 percent, Stupid Jokes at 15 percent and Random Complaints at 7 percent. Now let’s convert that to a bar chart.” ...