# Using/drawing Pie Charts

A Brief Explanation of how to use Pie Charts, particularly at GCSE Level

Date : 13/06/2022

### Author Information

Uploaded by : Zain
Uploaded on : 13/06/2022
Subject : Maths

Pie Charts are used to quickly represent the Proportions of each Group of Data.

We do this by taking `Slices` of a Circle, that are proportional towards the size of each group. For instance, in the chart below (showing Proportions of Native English speakers across the world), we give a Larger `Slice` to the USA since this is the country with the greatest amount of native English speakers. We also give a Larger `Slice` to the UK, compared to Canada and Australia.

The Proportion of each `Slice` will also be equal to the ;;Central Angle (Angle at Centre) of the `Slice`, divided by 360 Degrees. This is since within a Circle, the Sum of Angles are always 360 Degrees. Thus by dividing the Central Angle by this, we are thus dividing the Angle of ONE `Slice` by the Angle of ALL the Slices, within the Pie Chart.

Knowing these two things, we should be able to Construct Pie Charts given a Table of Data. An Example is shown below:

Comedy.  ;Action.  ;Romance.  ;;Drama.  ;Sci-Fi.  ; Total

;4  ;  ;  ;  ;  ;  ;  ;5  ;  ;  ;  ;  ;  ;  ; 6  ;  ;  ;  ;  ;  ;  ; 1  ;  ;  ;  ;  ;  ;  ;4.  ;  ;  ;  ;20

1). Looking at the table above, we first need to find the proportions of each Group of Data

-Comedy: 4/20 (4/Total)

-Action: 5/20 (5/Total)

-Romance: 6/20 (6/Total)

-Drama: 1/20 (1/Total)

-Sci-Fi: 4/20 (4/Total)

2). The Proportions will tell us the Proportion of Each `Slice` of the Pie Chart. We can use these Same Proportions to find the Central Angle of each `Slice`.

-Comedy: 4/20 x 360 = 72

-Action: 5/20 x 360 = 90

-Romance: 6/20 x 360 = 108

-Drama: 1/20 x 360 = 18

-Sci-Fi: 4/20 x 360 = 72

3). We can then use a Protractor to Draw each of these Slices with these Central Angles. This will allow us to Complete our Construction of a Pie Chart

Have a go at the Example shown below:

A Group of students perform a Maths Test. They produce the following Data. Draw a Pie Chart to Represent this.

A.  ;; B.  ;; C.  ;; D.

4.  ;; 10  ;; 12.  ;;2

This resource was uploaded by: Zain