#### Question

Draw a pie-diagram for the following data of the investment pattern in a five year plan:

Agriculture | Irrigation and Power | Small Industries | Transport | Social service | Miscellaneous |

14% | 16% | 29% | 17% | 16% | 8% |

#### Solution

We know:

Central angle of a component = (component value/sum of component values x 360)

Here the total percentage = 100%

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

Item | Amount (in %) |
Sector angle |

Agriculture | 14 | 14/100 x 360 = 50.4 |

Irrigation and Power | 16 | 16/100 x 360 = 57.6 |

Small Industries | 29 | 29/100 x 360 = 104.4 |

Transport | 17 | 17/100 x 360 = 61.2 |

Social Service | 16 | 16/100 x 360 = 57.6 |

Miscellaneous | 8 | 8/100 x 360 = 28.8 |

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 104.4^{o}. Draw a sector with the central angle 104.4^{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 the 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.