Question

Represent the following data by a pie-diagram:

Items of expenditure	Expenditure
	Family A	Family B
Food	4000	6400
Clothing	2500	480
Rent	1500	3200
Education	400	1000
Miscellaneous	1600	600
Total	10000	16000

Answer 1

We know:
Central angle of a component = (component value/sum of component values $\times$ 360)
Here the total expenditure of family A = 10000 and family B = 11680

Thus the central angle for each component can be calculated as follows:

Item	Expenditure (Family A)	Sector angle (Family A)	Expenditure (Family B)	Sector angle (Family B)
Food	4000	4000/10000 $\times$ 360 = 144	6400	6400/11680 $\times$ 360 = 197.3
Clothing	2500	2500/10000 $\times$ 360 = 90	480	480/11680 $\times$ 360 = 14.8
Rent	1500	1500/10000 $\times$ 360 = 54	3200	3200/11680 $\times$ 360 = 98.6
Education	400	400/10000 $\times$ 360 = 14.4	1000	1000/11680 $\times$ 360 = 30.8
Miscellaneous	1600	1600/10000 $\times$ 360 = 57.6	600	600/11680 $\times$ 360 = 18.5

Total expenditure of family A: 10000
Total expenditure of family B: 11680 (not 16000)

Now, the pie chat representing the given data can be constructed by following the steps below:
Step 1 : Draw 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 144^o. Draw a sector with the central angle 144^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 as in figure below.​​


Family A

Family B