In graph theory, a circle graph is the intersection graph of a set of chords of a circle. It is an undirected graph whose vertices can be associated with chords of a circle such that two vertices are adjacent if and only if the corresponding chords cross each other. The circle graph is also called a pie graph and pie chart.
Some important formulas of circle graph are given below:
1. Percentages = (Amount in the Category ⁄ Total) × 100
2. Angle = (Amount in the Category ⁄ Total) × 360°
Example 1: A fruit basket is filled with 36% Apples, 29% Bananas, 9% Mangoes, 7% Pineapples and 19% Grapes. Prepare a circle graph chart as per the data provided.
Example 2: The following data gives information about the number of different mobile phones used by the employees of one department in a company. Draw the circle chart for the following data using angle proportions.
|Mobile phone||Number of users|
Solution: Angle = (Amount in the Category ⁄ Total) × 360°
|Mobile phone||Number of users||Angle|
|Apple phone||9||(9/36) × 360° = 90°|
|HTC||12||(12/36) × 360° = 120°|
|Samsung||6||(6/36) × 360° = 60°|
|Sony||8||(8/36) × 360° = 80°|
|Nokia||1||(1/36) × 360° = 10°|
Example 3: The below table shows the percentage of expenses of a person in a month. Draw a circle chart for the data given.
|Category||Percentage of expense|
Food = 37%
Rent = 16%
Clothing = 11%
Education = 20%
Medicine = 4%
Other expenses = 12%