The document discusses the history and uses of pie charts. It begins with a brief history, noting that the earliest known pie chart is generally credited to William Playfair in 1801, and that Florence Nightingale later adapted it to make it more readable. It then provides details on what a pie chart is, how to make one including necessary formulas, different types of pie charts, and that while commonly used, pie charts have limitations for displaying large amounts of data compared to other chart types.

1. 50TH
JNNSME 2022-23
PIE CHART
THEME : “TECHNOLOGY AND TOYS”
SUB-THEME : MATHEMATICS FOR US
PRESENTED BY: SAAYAN PRATIT DASH (XII A ROLL: 21)
LALIT RANJAN KAR (XII A ROLL: 15)

2. HISTORY
The earliest known pie chart is generally credited to William Playfair's
Statistical Breviary of 1801, in which two such graphs are used. Playfair
presented an illustration, which contained a series of pie charts. One of
those charts depicted the proportions of the Turkish Empire located in Asia,
Europe and Africa before 1789. This invention was not widely used at first.
Playfair thought that pie charts were in need of a third dimension to add
additional information. Florence Nightingale may not have invented the pie
chart, but she adapted it to make it more readable, which fostered its wide
use, still today. Indeed, Nightingale reconfigured the pie chart making the
length of the wedges variable instead of their width. The graph, then,
resembled a cock's comb. She was later assumed to have created it due to
the obscurity and lack of practicality of Playfair's creation. The French
engineer Charles Joseph Minard also used pie charts, in 1858. A map of his
from 1858 used pie charts to represent the cattle sent from all around
France for consumption in Paris.

3. What is a pie chart?
A pie chart (or a circle chart) is a circular statistical graphic, which is
divided into slices to illustrate numerical proportion. In a pie chart,
the arc length of each slice (and consequently its Central angle and area)
is proportional to the quantity it represents. While it is named for its
resemblance to a pie which has been sliced, there are variations on the
way it can be presented. The earliest known pie chart is generally
credited to William Playfair's Statistical Breviary of 1801.
What the pie chart is depicting?
- The pie chart above depicts the concentration of gases in the
atmosphere.
- Red color shows the amount of nitrogen present in the atmosphere,
simultaneously green color shows the presence of oxygen, Blue shows
presence of other gases present in lower concentrations, Cyan shows
the presence of water vapor.

4. The exact concentration of gases present in the atmosphere is here shown
in the table above.

5. How to make a pie chart and necessary formulae used?
The pie chart is an important type of data representation. It contains
different segments and sectors in which each segment and sector of a pie
chart forms a specific portion of the total(percentage). The sum of all the
data is equal to 360°.
The total value of the pie is always 100%.
To work out with the percentage for a pie chart, follow the steps given
below:
 Categorize the data
 Calculate the total
 Divide the categories
 Convert into percentages
 Finally, calculate the degrees
Therefore, the pie chart formula is given as
(Given Data/Total value of Data) × 360°

6. USES AND ITS EFFECTIVENESS
A flaw exhibited by pie charts is that they cannot show more than a few
values without separating the visual encoding (the “slices”) from the data
they represent (typically percentages). When slices become too small, pie
charts have to rely on colors, textures or arrows so the reader can
understand them. This makes them unsuitable for use with larger amounts
of data. Pie charts also take up a larger amount of space on the page
compared to the more flexible bar charts, which do not need to have
separate legends, and can display other values such as averages or targets
at the same time.
Statesian generally regard pie charts as a poor method of displaying
information, and they are uncommon in scientific literature. One reason is
that it is more difficult for comparisons to be made between the size of
items in a chart when area is used instead of length and when different
items are shown as different shapes.

7. DIFFERENT TYPES OF PIE CHART
 3D pie chart and perspective pie cake
Doughnut chart

8. Exploded pie chart
Polar area Diagram

9. Ring chart, sunburst chart and multilevel pie chart
Spie chart

10. Square chart / Waffle chart