Question

Following is the break up of the expenditure of a family on different items of consumption:

Items	Food	Clothing	Rent	Education	Fuel etc.	Medicine	Miscellaneous
Expenditure (in Rs)	1600	200	600	150	100	80	270

Draw a pie-diagram to represent the above data.

Answer 1

We know:
Central angle of a component = (component value/sum of component values x 360)
Here, total expenditure = Rs 3000
Thus, central angle for each component can be calculated as follows:
 

Item	Expenditure (in Rs)	Sector angle
Food	1600	1600/3000 x 360 = 192
Clothing	200	200/3000 x 360 = 24
Rent	600	600/3000 x 360 = 72
Education	150	150/3000 x 360 = 18
Fuel etc	100	100/3000 x 360 = 12
Medicine	80	80/3000 x 360 = 9.6
Miscellaneous	270	270/3000 x 360 = 32.4

Total : 3000 (in Rs)

Now, the pie chat representing the given data can be constructed by following the steps below:
Step 1 : Draw a circle of an appropriate radius.
Step 2 : Draw a vertical radius of the circle drawn in step 1.
Step 3 : Choose the largest central angle. Here, the largest central angle is 192^o. Draw a sector with the central angle 192^o in such a way that one of its radii coincides with the radius drawn in step 2 and another radius is in its counter clockwise direction.
Step 4 : Construct other sectors representing the other items in the clockwise sense in descending order of magnitudes of their central angles.
​Step 5 : Shade the sectors with different colours and label them as shown in the figure below.​​