Question

The following data gives the amount spent on the construction of a house. Draw a pie diagram.

Items	Cement	Timber	Bricks	Labour	Steel	Miscellaneous
Expenditure (in thousand Rs)	60	30	45	75	45	45

Answer 1

We know:
Central angle of a component = (component value/sum of component values x 360)
Here. the total expenditures = 300 (in thousand Rs)
Thus the central angle for each component can be calculated as follows:
 

Item	Expenditure (in thousand Rs)	Sector angle
Cement	60	60/300 x 360 = 72
Timber	30	30/300 x 360 = 36
Bricks	45	45/300 x 360 = 54
Labour	75	75/300 x 360 = 90
Steel	45	45/300 x 360 = 54
Miscellaneous	45	45/300 x 360 = 54

Total expenditure: 300 (in thousand Rs)

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 90^o. Draw a sector with the central angle 90^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 direction 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.​​