Draw a pie-diagram of the areas of continents of the world given in the following table:
Continents | Asia | U.S.S.R | Africa | Europe | Noth America | South America | Australia |
Area (in million sq. km) |
26.9 | 20.5 | 30.3 | 4.9 | 24.3 | 17.9 | 8.5 |
We know:
Central angle of a component $=\left(\right.$ component value $/$ sum of component values $\left.\times 360^{\circ}\right)$
Here, total area in million sq km = 133.3
Thus, the central angle for each component can be calculated as follows:
Continent | Area (in million sq. km) | Sector angle |
Asia | 26.9 | 26.9/133.3 |
U.S.S.R | 20.5 | 20.5/133.3 |
Africa | 30.3 | 30.3/133.3 |
Europe | 4.9 | 4.9/133.3 |
North America | 24.3 | 24.3/133.3 |
South America | 17.9 | 17.9/133.3 |
Australia | 8.5 | 8.5/133.3 |
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 81.8o. Draw a sector with the central angle 81.8o 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 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.