# circle/pie graphs

### circle/pie graphs are important

## What is a pie chart

A type of graph in which a circle is divided into sectors that each represent a proportion of the whole.

## How do read a pie chart

*Pie charts are perhaps the most ubiquitous chart type; they can be found in newspapers, business reports, and many other places. But few people actually understand the function of the pie chart and how to use it properly. In addition to issues stemming from using too many categories, the biggest problem is getting the basic premise: that the pie slices sum up to a meaningful whole.*## What is a sector on the pie chart

Pie charts display the distribution of data with sectors that are sized proportionally to the number of objects in each group. To draw a pie chart accurately, you need to find the angle of each sector in the chart. You can work out the angles for a pie chart following the step by step instructions below, or you can use the convenient pie chart calculator on the left. Simply fill in the blanks in the first column for the number of objects in each group. The calculator will output the percentages and angles in the second and third columns.

## What the sum of all sectors

the sum of all sectors is 100% or one whole