Bar Diagrams and Pie Diagrams Class 11 Notes

Diagrammatic presentation is broadly classified into three types:

1. Geometric Form
2. Frequency Diagrams
3. Arithmetic Line Graphs or Time Series Graphs

Bar diagrams and pie diagrams are part of the geometric form. In this chapter, we are going to learn more about bar diagrams and pie diagrams.

Bar

Bar usually means a rectangle or some rectangular form. It shows some value of the variable. It has the following features:

• The length or height of the bars differs according to different values of the variable, that is length may be more or less but breadth remains the same.
• Bars are equidistant from each other.
• All are based on some common baseline.
• Bars may be either vertical or horizontal.

Bar Diagram

Bar diagrams are those diagrams in which data are presented in the form of bars or rectangles. Bars are also called columns.

Types of Bar Diagrams

1) Simple Bar Diagrams

These are those diagrams that are based on a single set of numerical data. The different items or values are represented by different bars.

2) Multi Bar Diagrams

These are those diagrams that show two or more sets of data simultaneously. Generally, these diagrams are used to make comparisons between two sets of series, such as birth rate and death rate series.

3) Sub-divided Bar Diagrams

These are those diagrams which are simultaneously present, total values as well as part values of a set of data.

4) Percentage Bar Diagrams

These are those diagrams that show simultaneously, different parts of the values of a set of data in terms of percentages.

5) Deviation Bar Diagrams

These diagrams are used to compare the net deviation of related variables concerning time and location.

Organization of Data Class 11 Notes

Pie or Circular Diagrams

A pie diagram is a circle divided into various segments showing the percent values of a series. The diagram does not show absolute values.

Construction of a Pie Diagram

Construction of a pie diagram involves the following steps:

• As a first step, the absolute values of the series are converted into percent values.
• Second, draw a circle and note the fact within a circle we can draw 4 angles of 90 degrees each.
• Show each value in the circle clockwise.

These are the notes on the bar diagram and pie diagram. If you have any doubt related to this concept, you can ask that in the comment section. I will try to resolve that doubt as fast as possible.