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

Solution:

We know:

Central angle of a component $=$ (component value/sum of component values $\times 360^{\circ}$ )

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 ×× 360 = 72 Timber 30 30/300 ×× 360 = 36 Bricks 45 45/300 ×× 360 = 54 Labour 75 75/300 ×× 360 = 90 Steel 45 45/300 ×× 360 = 54 Miscellaneous 45 45/300 ×× 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 90o. Draw a sector with the central angle 90o 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.​​