Data Interpretation Pie Chart : Theory & Concepts

Pie graphs are circular shaped graphs which are divided into sectors or slices to represent numerical data. In a pie chart, the length or central angle of each sector or slice is proportional to the quantity it represents.

You should learn how to make a pie chart, so as to answer the questions based on the same with ease. While making a pie chart, every component is graphed in such a manner such that the size of the pie it represents corresponds to its real value on a relative basis i.e. the size of the slices shows the relative size of the categories. Pie charts use values or percentage or angles to show the relative sizes of various categories. In simple words, the bigger the slice of the pie, the higher is the proportion out of the total that it represents. Please read & understand the following tips and tricks to solve pie chart problems effectively.

Let us consider Pie-chart as a circle. You can solve Pie chart problems using the properties of a circle and the basic concept of percentages. A whole circle contains 360 degrees. In a pie chart, these 360 degrees corresponds to the total of the values represented in the chart. For example 360 degree might correspond to a class of 100 students studying in a school. On the other hand, the distribution might be in terms of percentages, which sums up to 100% i.e 100 students now correspond to 100 percent.  Therefore 360 degrees = 100 % = 100 students. We can easily differentiate the entire class into different groups based upon the question statement.

Pie chart formulas and Important points:
Total angle at the center of a pie chart = 360⁰
To convert x% into angle = (x/100) × 360 e.g. for 10 %, (10/100) x 360=36⁰ i.e. 10% forms a 36⁰ Angle at the center and vice-versa. To convert m⁰ into percentage = (m/360) ×100

Before solving the questions of your own, you must understand a few of the pie chart questions and answers. As most of the exams are online these days, so you must practice some pie charts online.