Page 261 - ICSE Math 8

Step 3: Draw a circle of any radius.
Step 4: Draw a horizontal line as the radius of the circle.

Step 5: Starting with this horizontal radius and moving in clockwise direction, draw sectors using the central
angles calculated in step 2 one at a time till all the components are exhausted.

Step 6: Shade the sectors using different colours/designs and name them.

Reading a pie chart
The process of obtaining various information related to the given data from a given pie chart is known as
reading pie chart.
For reading a pie chart, we need to know the following results:

Central angle of the component Total value of all the co× m mponents
(i) Value of a component = 
360
Central angle of the component 100×
(ii) Percentage value of a component = 
360

Example 7: There are 900 creatures in a zoo as per the table given below:

Water Other land
Kind of creature Birds Reptiles Beasts
animals animals
No. of creatures 125 50 150 175 400

Represent the above data in a pie chart.

Solution: Total number of creatures = 900

Ê Number of creatures ofa kind ˆ
Central angle for a creature = Á Total numberofcreatures ¥ 360 ˜ ¯
Ë
Calculation of Central Angle

Kind of creature No. of creatures Central angle

 125  °
Birds 125  × 360  = 50°
 900 

 50  °
Reptiles 50  × 360  = 20°
 900 

Ê 150 ˆ ∞
Beasts 150 Á Ë 900 ¥ 360 ˜ = 60°
¯

Ê 175 ˆ ∞
Water animals 175 Á Ë 900 ¥ 360 ˜ = 70°
¯

 400  °
Other land animals 400  × 360  = 160°
 900 

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