Page 201 - Maths Skills - 8

Data Handling 199

Now, follow these steps to construct a pie chart.
Step 1: Draw a circle of any convenient radius.

Step 2: Draw a horizontal radius of the circle.
Step 3: Draw sectors starting from the horizontal radius with central
angles of 54°, 72°, 36°, 90° and 108° respectively.
Step 4: Shade the sectors differently using different colours and label them.
Thus, we obtain the required pie chart as shown in the adjoining figure.

Example 2: The following data represents the favourite types of movies of a group of friends. Represent this
data through a pie chart.

Favourite Types of Movies
Comedy Action Romance Drama SciFi

4 5 6 1 4

Solution: We need to figure out how many degrees for each “pie slice” (correctly called a sector).

A full circle has 360 degrees, so we do the following calculation

Movies Number of friends Central angle
Thus, we obtain the required
Comedy 4 4/20 × 360° = 72° pie chart as below.

Action 5 5/20 × 360° = 90°
Romance 6 6/20 × 360° = 108°

Drama 1 1/20 × 360° = 18°

SciFi 4 4/20 × 360° = 72°

TOTAL 20 360°

Example 3: The pie chart given below shows the sources of funds to be collected by the National Highways
Authority of India (NHAI) for its Phase II projects.
Study the pie-chart and answer the questions that follow.
Sources of funds to be arranged by NHAI for Phase II projects
(in crores `)

(i) Where is the maximum number of funds required?
(ii) What percentage of funds is required for Toll?
(iii) What is the central angle corresponding to Annuity?

(iv) What is the approximate ratio of funds to be arranged through SPVS and Market Borrowing?

Solution: (i) Looking at the pie chart, we can conclude that market borrowing requires the maximum funds.
(ii) Funds for Toll: ` 4910
Total funds: = ` 11,486 + ` 5252 + ` 4910 + ` 6000 + ` 29,952 = ` 57,600
( 4910 )
Percentage of funds for Toll = 57600 × 100 = 8.5 %