Pie Chart: The pie chart is a graph, where the data is represented by a circular graph. Pie charts fall under the category of pictorial representation of data, where the slices of a pie chart represent the quantity of data. In a pie chart, the length of the arc and central angle of each slice is proportional to the quantity represented.

When we want to show information such as the amount of money spent on different expenses on a school trip, plan a monthly budget, or show the percentage of ingredients in a juice, such type of information has more impact when represented visually through a pie chart. When we cut specific percentage areas from a circle, it looks like slices made on a pie, which is why such a chart is called a pie chart. On this page, we have provided all the necessary information about Pie charts and how to create a Pie Chart with the help of data.

Pie Chart or Pie Diagram

 

A Pie Chart or Pie Diagram is a statistical graph that visualises the data by using a circular graph. The pie chart is the most used graph to represent the data by using circles and spheres. Each part of the pie chart is divided into parts and each part is known as sector.

The term Pie means “whole”, and slices of the pie (whole) represent the parts of the pie. Pie Chart is otherwise called a Circle Chart. With the help of Pie slices, we can tell the relative sizes of the data.

 

Pie Chart Example

 

Below Pie Chart describes the time spent by a child in a day.

 

 

Pie Chart Formula

 

Pie chart is the most used graphical representation in statistics. Pie chart has different sectors and each sector occupies some part of the total (percentage).

 

The total value of the pie chart is always taken as \(100\,\% \).

 

The pie chart is expressed in terms of the degrees, and we know that the total of all the data of the pie chart is \(360\) degrees.

 

So, to draw the pie chart we need to work out with the pie chart, following are the steps to be followed:

 

1. Categorise the given data 
2. Observe the total of the given data 
3. Divide the data into parts 
4. Convert the data into percentages 
5. Now calculate the data into degrees

 

Pie chart formula\( = \frac{{{\rm{ Given}}\,{\rm{data }}}}{{{\rm{ total}}\,{\rm{value}}\,{\rm{of}}\,{\rm{the}}\,{\rm{data }}}} \times {360^{\rm{o}}}\)

 

 Therefore, the pie chart formula is given by

The above formula is used to draw a pie chart.

Calculation for Pie Chart

 

For a given pie chart, we can get the value of each sector by measuring the angle made by each part.

 

The percentage of each part of the pie chart can be calculated as follows:

 

1. Measure the angle of each part
2. Divide it with \({360^{\rm{o}}}\)
3. Multiply it with \(100\)

 

Example: The below pie chart shows the diet followed in a day.

 

 

To find the percentage of each part, we divide it with \({360^{\rm{o}}}\) and multiply it with \(100.\)

 

Protein\( = \frac{{{{180}^{\rm{o}}}}}{{360}} \times 100 = 50\% \)

 

Carb\( = \frac{{{{108}^{\rm{o}}}}}{{360}} \times 100 = 30\% \)

 

Fats\( = \frac{{{{72}^{\rm{o}}}}}{{360}} \times 100 = 20\% \)

 

Reading a Pie Chart

 

To read or evaluate pie chart, we can see pie chart given in percentages or with any value. If it is given in percentages, the conversion is made and evaluated accordingly.

 

Example: Below pie chart shows the types of transportation used by \(1000\) students to come to school.

 

 

The number of students coming to school by bicycle is given by
\(\frac{{25}}{{100}} \times 1000 = 250\)

 

The number of students coming to school by bus is given by
\(\frac{{26}}{{100}} \times 1000 = 260\)

 

The number of students coming to school by walking is given by
\(\frac{{17}}{{100}} \times 1000 = 170\)

 

The number of students coming to school by car is given by
\(\frac{{32}}{{100}} \times 100 = 320\)

 

Construction of a Pie Chart

 

The steps to create a pie chart are given below:

 

1. Classify the given data based on the categories.
2. Calculate the total value of the data by adding all the given values.
3. Divide the value of each category with the total value.
   \(\frac{{{\rm{ Frequency }}}}{{{\rm{ Total}}\,{\rm{frequency }}}} \times {360^{\rm{o}}}\)
4. Convert the result into a percentage.
5. Now percentages should be converted to degrees and the degrees should be represented in the pie.

 

 

Example:
Let us construct a pie chart for the number of fruits eaten by the students in a class:

 

Mango	Orange	Plum	Pineapple	Melon
\(45\)	\(30\)	\(15\)	\(30\)	\(30\)

 

Total frequency \(150.\)

 

Category	Formula	Degrees
Mango	\(\frac{{45}}{{150}} \times {360^{\rm{o}}}\)	\({108^{\rm{o}}}\)
Orange	\(\frac{{30}}{{150}} \times {360^{\rm{o}}}\)	\({72^{\rm{o}}}\)
Plum	\(\frac{{15}}{{150}} \times {360^{\rm{o}}}\)	\({36^{\rm{o}}}\)
Pineapple	\(\frac{{30}}{{150}} \times {360^{\rm{o}}}\)	\({72^{\rm{o}}}\)
Melon	\(\frac{{30}}{{150}} \times {360^{\rm{o}}}\)	\({72^{\rm{o}}}\)

 

Draw a circle of any radius. With the radius as a base, by using protractor construct \({108^{\rm{o}}}\) in the circle. Construct all other sectors by using the protractor with their given values.

 

The pie chart drawn for the above data is as follows:

 

Uses of Pie Chart

When the data must be represented graphically as a fractional part of the whole, we can use pie charts. Pie charts are used to visualise the data as the percentage of the total. The pie chart is used in real-life in many ways, such as:

1. To represent the different fruits, games liked by a student in class.
2. To compare the statistical data of education, population among the cities, states, or countries.
3. Used to compare the profit, turnover in a business.
4. Few Pie Chart examples are given below:
   • (a). The number of slices divided in Pizza
   • (b). Number of parts in car wheel
   • (c). Number of the pieces made in a watermelon
   • (d). Number of slices made in donut

 

 

Advantages of Pie Chart

 

The few advantages of the pie chart as listed below:
1. It is simple and easy to understand.
2. Easily, data can be represented as a fractional part of the whole.
3. Pie chart shows discrete data in the circular graph.
4. It is easy to compare the various parts of the pie chart.

 

Disadvantages of Pie Chart

 

Even though it is simple, it has a few disadvantages also, such as:
1. If there are too many parts, then it is less effective.
2. It cannot be used to analyse the data quickly.
3. It provides only one type of data set.

 

Types of Pie Chart

 

Pie charts are mainly classified into two types based on the dimension:
They are:
1. \(2D\) Pie Chart
2. \(3D\) Pie Chart

2D Pie Chart

A two-dimensional pie chart describes the entire data in two dimensions. There are mainly four types of pie chart under this and they are

 

1. Simple Pie Chart

This chart shows the parts of each value to the total.

 

 

2. Exploded Pie Chart

 

When one sector or all the sectors of the Pie Chart are broken down from the centre and pulled out, then it is called an Exploded Pie Chart. This is shown in the figure below.

 

 

3. Pie of Pie

 

In this, the pie chart extracts some values from the main pie chart and another pie chart is created to observe and analyse the data inside it.

 

4. Bar of Pie

 

In this, the pie chart extracts some values from the main pie, and it combines them to form a stacked bar.

 

 

3D Pie Chart

 

It is a chart based on the three dimensions. It is the chart used to compare the aesthetic reasons such as nature, rivers, mountains, flowers, etc. It is subdivided into two categories, such as

 

1. Simple 3D Pie Chart

 

It visualises the data in three axes, such as \(x, y, z.\)

 

 

2. Exploded 3D Pie Chart

 

It is the three-dimensional version of the exploded pie chart.

 

Solved Examples on Pie Chart

 

Q.1. The below pie chart shows the favourite subjects of the students in a class:

 

 

Using the above information, find what percentage of students likes English subjects?
Ans: We know that total value of the pie chart is \({360^{\rm{o}}}\), which is the sum of all the given values.
The percentage of students, who like English is given by \(\frac{{{\rm{Given}}{\mkern 1mu} {\rm{value}}}}{{{\rm{total}}{\mkern 1mu} {\rm{value}}}}{\rm{ \times 100}}{\rm{.}}\)
\( = \frac{{72}}{{360}} \times 100\)
\( = \frac{{100}}{5} = 20\% \)
So, the percentage of students who likes English is \(20\% \).

 

Q.2. Construct a pie chart for the number of fruits eaten by the students in a class. Draw a circle with a compass with any radius.

 

Mango	Orange	Plum	Pineapple	Melon
\(90\)	\(60\)	\(30\)	\(60\)	\(60\)

 

Ans:
Total frequency \(300.\)

 

 

The pie chart drawn for the above data shown as follows:

 

 

Q.3. The below pie chart shows the favourite subjects of the students in a class:

 

 

Using the above information, find how many students likes Mathematics subject, if the class strength is \(40.\)
Ans: We know that total value of the pie chart is \({360^{\rm{o}}},\) which is the sum of all the given values.
The percentage of students, who like Mathematics is given by \(\frac{{{\rm{ Given}}\,{\rm{value}}}}{{{\rm{ total}}\,{\rm{value}}}} \times 100.\)
\( = \frac{{144}}{{360}} \times 100\)
\( = \frac{{200}}{5} = 40\% \)
So, the percentage of students who likes Mathematics is \(40\% \).
So, number of students, who likes Mathematics is given by \(40\% \) of \(40.\)
\(\frac{{40}}{{100}} \times 40 = 16\)
So, there are \(16\) students in a class, who like Mathematics.

 

Q.4. The following pie chart shows the activities of Soumya in a week. Find the central angle subtended at the centre and also find the portion spent in sleeping.

 

 

Ans: The central angle of each part is given by \(\frac{{{\rm{ Given}}\,{\rm{value}}}}{{{\rm{ 100}}}} \times {360^{\rm{o}}}\)
\( = \frac{{25}}{{100}} \times 360 = {90^{\rm{o}}}\)
The portion of the chart, spent on sleeping is \(25\% \).
\( = \frac{{25}}{{100}} = \frac{1}{4}\).

 

Q.5. Sanjay bought different kinds of fruits from his farm as follows:

 

Fruit Type	Banana	Apple	Mango	Pineapple
Number of fruits	\(42\)	\(14\)	\(9\)	\(7\)

 

Prepare the pie chart for the above data.
Ans: \(42+14+9+7=72\)

 

Fruit	Number of fruits	Central angle
Banana	\(42\)	\(\frac{{42}}{{72}} \times {360^{\rm{o}}} = {210^{\rm{o}}}\)
Apple	\(14\)	\(\frac{{14}}{{72}} \times {360^{\rm{o}}} = {70^{\rm{o}}}\)
Mango	\(9\)	\(\frac{{9}}{{72}} \times {360^{\rm{o}}} = {45^{\rm{o}}}\)
Pineapple	\(7\)	\(\frac{{7}}{{72}} \times {360^{\rm{o}}} = {35^{\rm{o}}}\)

 

The pie chart for the above data is shown below (Colours used: Banana-blue colour, Apple-orange colour, Mango-grey colour and Pineapple-yellow colour):

 

 

Summary

 

In this article, we have provided all the necessary information about Pie charts and how to create a Pie Chart with the help of data. Pie Chart is a graph, where the data is represented in the form of a circular graph. Pie Charts fall under the category “pictorial representation of data”. Pie charts are very simple and easy to understand.

Frequently Asked Questions (FAQs) About Pie Chart

Let’s look at some of the frequently asked questions about the Pie Chart:

Q.1. What is Pie chart, explain with an example?
Ans: Pie chart is a statistical graph that visualises the data by using a circular graph.
Examples:
a. To represent the different fruits, games liked by a student in the class.
b. To compare the statistical data of education, population among the cities, states, or countries.

Q.2. How do we use pie charts?
Ans: Pie charts are used to denote relative data are proportional data in a single circular graph the slices of the pie chart are used to compare the percentage of a part in the whole.

Q.3. What is the formula for a pie chart?
Ans: Pie charts are calculated by using the formula:
\(\frac{{{\rm{ Central}}\,{\rm{angle }}}}{{{{360}^{\rm{o}}}}} \times 100\)

Q.4. What are the advantages of the pie chart?
Ans: Some of the advantages of Pie Charts are given below:
a. It is simple.
b. It is easy to understand.
c. Easily, data can be represented as a fractional part of the whole.

Q.5. How do you describe a pie chart in Statistics?
Ans: Pie chart is a circular chart that is divided into slices based on numerical proportions to represent data.

 

Now you are provided with all the necessary information regarding Pie Chart. Students can make use of NCERT Solutions provided by Embibe for their exam preparation.

 

Class 8 Maths Practice Questions	Class 8 Maths Mock Test
Class 9 Maths Practice Questions	Class 9 Maths Mock Test
Class 10 Maths Practice Questions	Class 10 Maths Mock Test
Maths Practice Questions for Class 11 & 12	Maths Mock Test for Class 11 & 12

 

Download Class 8 Maths Formulas From Here

 

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