In these lessons, we will learn:
Related Pages
Graphical Methods For Describing Data
Bar Charts
Statistics Lessons
A pie chart (also called a Pie Graph or Circle Graph) makes use of sectors in a circle. The angle of a sector is proportional to the frequency of the data.
The following diagram shows how to use the formula to determine the angle of each sector in a circle graph or pie chart.
Study the following steps of constructing a circle graph or pie chart:
Step 1: Calculate the angle of each sector, using the formula.
Step 2: Draw a circle using a pair of compasses.
Step 3: Use a protractor to draw the angle for each sector.
Step 4: Label the circle graph and all its sectors.
Example:
In a school, there are 750 students in Year1, 420 students in Year 2 and 630 students in Year 3.
Draw a circle graph to represent the numbers of students in these groups.
Solution:
Total number of students = 750 + 420 + 630 = 1,800.
Draw the circle, measure in each sector. Label each sector and the pie chart.
Steps to making a circle graph:
This video shows how to construct a circle graph from the given data.
This video shows how to draw a pie chart by working out angles from a table.
Example: The table shows 18 people’s favorite color. Display the information as a pie chart.
Try the free Mathway calculator and
problem solver below to practice various math topics. Try the given examples, or type in your own
problem and check your answer with the step-by-step explanations.
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