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The pie chart represents data in a circular graph. The pieces of the chart or graph show the data size. The various components are represented by the pieces of a circle and the whole circle is the sum of the values of all components. One can get the pie chart definition, formula, use, solved examples, and steps to create a pie chart in the below sections.

## Pie Chart Definition

A pie chart is also a graph and is a type of pictorial representation of data. It divides the circle into various sectors in order to explain the numeric values. Each section is a proportionate part of the whole circle. We use a pie chart to find the composition of something. The pie chart is also known as the circle chart.

A pie chart is used for data representation. The total of all data in a pie is equal to 360° and the total value of a pie is always 100%.

The central angle for a component formula is given as

Central angle for a component = (Value of the component / Sum of the values of all components) * 360°

### Steps to Make a Pie Chart

Follow the below-mentioned steps to create a pie chart/ circle chart for the given data.

- Enter the given data into a table to make the process easy for you.
- Find the sum of values in the table.
- Divide each value in the table by sum and multiply the result with 100 to get the percent.
- To get the degrees of each value, substitute the values in the formula i.e (Value of each component/sum) * 360A pie chart is used for the data representation. The total of all data in a pie is equal to 360° and the total value of a pie is always 100%.
- The central angle for a component formula is given as Central angle for a component = (Value of the component / Sum of the values of all components) * 360°.
- Draw a circle and use a protractor to measure the degree of each sector.

### Advantages and Disadvantages of Pie Chart

Advantages

- It is simple and easy to understand
- Data can be represented visually as a fractional part of the whole.
- It helps in providing an effective communication tool for the uninformed audience.

Disadvantages

- It can represent only one set of data. So, you need a series to compare multiple sets.
- If you have too many pieces of data, and even you add labels and numbers may not help here, they themselves may become crowded and hard to read.

### Example Questions & Answers

**Example 1.**

The following table shows the expenditure in percentage incurred on the construction of a house in a city:

Item | Brick | Cement | Steel | Labour | Miscellaneous |
---|---|---|---|---|---|

Expenditure (in percentage) | 18% | 30% | 10% | 12% | 30% |

Draw a pie chart for the above data.

**Solution:**

Total percentage = 100

Central angle for a component = (Value of the component / Sum of the values of all components) * 360°

Calculation of central angles:

Item | Expenditure (in percentage) | Central Angle |
---|---|---|

Brick | 18% | ((18 / 100) * 360°) = 64.8° |

Cement | 30% | ((30 / 100) * 360°) = 108° |

Steel | 10% | ((10 / 100) * 360°) = 36° |

Labour | 12% | ((12 / 100) * 360° = 43.2° |

Miscellaneous | 30% | ((30 / 100) * 360°) = 108° |

Construction for creating a pie chart

Steps of construction:

1. Draw a circle of any convenient radius.

2. Draw a horizontal radius of the circle.

3. Draw sectors starting from the horizontal radius with central angles of 64.8°, 108°, 36°, 43.2°, and 108° respectively.

4. Shade the sectors differently using different colors and label them.

Thus, we obtain the required pie chart, shown in the above figure.

**Example 2.**

The marks scored by a student in his examination are shown below:

Subject | English | Hindi | Maths | Science | Social |
---|---|---|---|---|---|

Marks | 70 | 85 | 76 | 88 | 92 |

Draw a pie chart for the above data.

**Solution:**

The given table contains the marks of a student in an exam.

The total marks scored by a student = 411

Central angle for a component = (Each subject marks / total marks) * 360°

Calculation of central angles:

Subject | Marks | Central Angle |
---|---|---|

English | 70 | (70 / 411) * 360° = 61.31° |

Hindi | 85 | (85 / 411) * 360° = 74.45° |

Maths | 76 | (76 / 411) * 360° = 66.56° |

Science | 88 | (88 / 411) * 360° = 77.08° |

Social | 92 | (92 / 411) * 360° = 80.58° |

Construction for creating a pie chart

Steps of construction:

1. Draw a circle.

2. Draw sectors starting from the horizontal radius with central angles of 61.31°, 74.45°, 66.56°, 77.08°, 80.58° respectively.

3. Shade the sectors differently using different colors and label them.

Thus, we obtain the required pie chart, shown in the above figure.

**Example 3.**

The data on the mode of transport used by 1000 students are given below:

Mode of Transport | Bus | Cycle | Train | Car | Scooter |
---|---|---|---|---|---|

Number of Students | 150 | 50 | 200 | 100 | 500 |

Represent the data on a pie chart.

**Solution:**

The given table shows the mode of transport used by 1000 students to reach the school.

Total Number of Students = 1000

Central angle for a component = (Value of the component / Sum of the values of all components) * 360°

Calculation of central angles:

Mode of Transport | Number of Students | Central Angle |
---|---|---|

Bus | 150 | (150 / 1000) * 360 = 54° |

Cycle | 50 | (50 / 1000) * 360 = 18° |

Train | 200 | (200 / 1000) * 360 = 72° |

Car | 100 | (100 / 1000) * 360 = 36° |

Scooter | 500 | (500 / 1000) * 360 = 180° |

Construction for creating a pie chart

1. Draw a circle of any convenient radius.

2. Draw a horizontal radius of the circle.

3. Draw sectors starting from the horizontal radius with central angles of 54°, 18°, 72°, 36°, and 180°.

4. Shade the sectors differently using different colors and label them.

Thus, we obtain the required pie chart, shown in the above figure.

### FAQs on Pie Chart

1. What are the uses of a pie chart?

A pie chart is used to represent categorical data, to compare areas of growth in a business like turnover profit and exposure.

2. What are the pie chart examples?

The real-life examples of the pie charts are a representation of kinds of cars sold in a month, types of food items liked by people in a room, marks scored by students in a class, etc

3. What is the formula to calculate the percentage of each component of a pie chart?

The pie chart formula to calculate the central angle for a component is as follows: