 # Pie Chart

The “pie chart” also is known as “circle chart” divides the circular statistical graphic into sectors or slices in order to illustrate the numerical problems. Each sector denotes a proportionate part of the whole. To find out the composition of something, Pie-chart works the best at that time. In most of the cases, pie charts replace some other graphs like the bar graph, line plots, histograms etc.

## Pie Chart Formula

The pie chart is an important type of data representation. It contains different segments and sectors in which each segment and sectors of a pie chart forms a certain portion of the total(percentage). The total of all the data is equal to 360°.

The total value of the pie is always 100%.

To work out with the percentage for a pie chart, follow the steps given below:

• Categorize the data
• Calculate the total
• Divide the categories
• Convert into percentages
• Finally, calculate the degrees

Therefore, the pie chart formula is given as

(Given Data/Total value of Data) × 360°

## Pie Chart Example

Imagine a teacher surveys her class on the basis of their favourite Sports:

The data above can be represented by a pie-chart as following and by using the circle graph formula i.e. the pie chart formula given below. It makes the size of portion easy to understand.

Step 1: First, Enter the data into the table.

Step 2: Add all the values in the table to get the total.

I.e Total students are 40 in this case.

Step 3: Next, divide each value by the total and multiply by 100 to get a per cent:

 Football Hockey Cricket Basketball Badminton (10/40) × 100 =25% (5/ 40) × 100 =12.5% (5/40) ×100 =12.5% (10/ 40) ×100 =25% (10/40)× 100 =25%

Step 4: Next to know how many degrees for each “pie sector” we need, we will take a full circle of 360° and follow the calculations below:

The central angle of each component = (Value of each component/sum of values of all the components)✕360°

 Football Hockey Cricket Basketball Badminton (10/ 40)× 360° =90° (5 / 40) × 360° =45° (5/40) × 360° =45° (10/ 40)× 360° =90° (10/ 40) × 360° =90°

Now you can draw a pie chart.

Step 5: Draw a circle and use the protractor to measure the degree of each sector. ## Uses of Pie Chart

Within a business, it is used to compare areas of growth such as turnover, profit, and exposure.
To represent categorical data. ### Advantages of a Pie Chart

• The picture is simple and easy-to-understand
• Data can be represented visually as a fractional part of a whole
• It helps in providing an effective communication tool for the even uninformed audience
• Provides a data comparison for the audience at a glance to give an immediate analysis or to quickly understand information
• No need for readers to examine or measure underlying numbers themselves which can be removed by using this chart
• To emphasize a few points you want to make, you can manipulate pieces of data in the pie chart

### Disadvantages of a Pie Chart

• It becomes less effective, If there are too many pieces of data to use
• If there are too many pieces of data, and even if you add data labels and numbers may not help here, they themselves may become crowded and hard to read
• As this chart only represents one data set, You need a series to compare multiple sets
• This may make it more difficult for readers when it comes to analyze and assimilate information quickly

You can practice another pie chart question for class 8 given below:

### Pie Chart Question

Question: Priya lists down her monthly expenditure as follows:

 Expenditure Amount Rent 4000 Food 5400 Clothing 2800 Savings 400

Draw a pie chart for her monthly expenses.

You might also like to practice some more Mathematical topics. Download BYJU’S- The Learning App for a variety of topics and concepts to learn from.