2014-02-22T19:40:23+01:00
I hope you understand this brief tutorial, although it's best done with visual aid!

Garri  -  80bags
Rice  -  45bags
Beans - 35bags
Cocoyam  -  20bags
(The above information represent the amount (in bags) of crops produced by a farmer in 2013; represent the information on a pie chart.)

Pie charts are actually like percentages. In percentages, you talk about per cent, i.e. out of 100, but in pie charts, it is out of a certain totalled amount, and then 360.
Oh! let's see how.

How many bags in total?
Yes, 180 bags - 80 + 45 + 35 + 20 = 180

Now, represent each good as a fraction of the whole, 180.

Garri =
Rice =
Beans =
Cocoyam = =

Then, represent each as a part of a whole circle, 360.

Garri = = 160°
Rice = = 90°
Beans = = 70°
Cocoyam = = 40°

Did you check to see if 160° + 90° + 70° + 40° = 360°?

1. Use a pair of compass to draw a circle.
2. Starting from the centre, draw a line to touch the circumference at any point.
3. Place your protractor on that line and mark off 160° on your protractor.
4. Remove the protractor and use a ruler to draw a line from that mark to the centre.
5. Place the protractor again on the new line and mark off 90°.
6. Remove the protractor again and draw a line from the new mark to the centre.
7. Repeat steps 5 and 6 for angles 70° and 40° as you go round the circle.