A pie chart can used to compare the relation between the whole and its components. A pie chart is a circular diagram and the area of the sector of a circle is used in a 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 means of a protractor to show different components. The arrangement of the sectors is usually anti-clock wise.
The following table gives the details of monthly budget of a family. Represent these figures by a suitable diagram.
Item of Expenditure
The necessary computations are given below: