A pie chart is a graphical way to organize data. Pie charts are used for showing classes or groups of data in proportion to a whole data set. The entire pie represents all the data, while each slice represents a different class or a group within the whole. A pie graph (or pie chart) is a specialized graph used in statistics. The independent variable is plotted around a circle in either the clockwise or the counterclockwise direction. The dependent variable (usually a percentage) is rendered as an arc whose measure is proportional to the magnitude of the quantity. Each arc is depicted by constructing radial lines from its ends to the center of the circle, creating a wedge-shaped "slice." The independent variable can attain a finite number of discrete values (for example, five). The dependent variable can attain any value from zero to 100 percent.

Features of modern software Pie charts:

• Pie chart shows the largest piece to find the most common class.
• Pie chart has elative sizes of pieces. Some classes might be unexpectedly similar or different in size.
• Pie chart can be two- or three- dimensional view of the pie; 3D pie charts are attractive but they can make pieces at the front of the picture look bigger than they really are.