Pie Chart
Pie chart can used to compare the relation between the whole and its components. Pie chart is a circular diagram and the area of the sector of a circle is used in pie chart. Circles are drawn with radii proportional to the square root of the quantities because the area of a circle is .
To construct a pie chart (sector diagram), we draw a circle with radius (square root of the total). The total angle of the circle is . The angles of each component are calculated by the formula.
These angles are made in the circle by mean of a protractor to show different components. The arrangement of the sectors is usually anticlock wise.
Example:
The following table gives the details of monthly budget of a family. Represent these figures by a suitable diagram.
Item of Expenditure 
Family Budget

Food


Clothing


House Rent


Fuel and Lighting


Miscellaneous


Total


Solution:
The necessary computations are given below:
Items 
Family Budget


Expenditure $

Angle of Sectors

Cumulative Angle


Food




Clothing




House Rent




Fuel and Lighting




Miscellaneous




Total



