Pie Chart 1: How to draw a pie chart S. Kelleher
Fraction of a circle = number of people in a category total number of people in the survey 3600
Genre Sport Sci-fi Drama Documentary Frequency 29 25 10 8 EXAMPLE 72 People were surveyed about which type of T.V. programme was their favourite. The results were: Genre Sport Sci-fi Drama Documentary Frequency 29 25 10 8 Draw a pie-chart for the information in the table above TYPE/CATEGORY HOW OFTEN
Calculating the angles Fraction of a circle = number of people in a category total number of people in the survey 3600 SPORT = 29 72 3600 = 1450 CATEGORY TOTAL SURVEY TOTAL SCI-FI = 25 72 3600 = 1250 NOTE: When doing calculations round to the nearest whole number of degrees DRAMA = 10 72 3600 = 500 DOCUMENTARY = 8 72 3600 = 400 CHECK: Total = 3600
Drawing the angles IGNORE THIS PART OF THE PROTRACTOR WHEN TAKING MEASUREMENTS OR DRAWING CIRLCES
⑤ Spin the protractor around ⑥ Draw the bottom half of the circle ④ Trace the protractor outline ③ Sit the protractor on the cross-hair ② Draw a horizontal line from the cross-hair ① Draw a cross-hair
⑧ Draw a line from the cross-hair to the mark ⑦ Sit the protractor on the cross-hair and mark the first angle: 1450
⑨ Spin the protractor around until it matches up with the line you drew for the first angle. ⑪ Draw a line between the cross-hair and the mark. ⑩ Mark the next angle by counting from the first line you have drawn. Angle = 1250
⑫ Spin the protractor around until it matches up with the second line ⑭ Draw a line from the cross-hair to the mark. ⑬ Count from this line and place a mark for the next angle. Angle = 500
⑮ The final angle is automatically drawn, so only labels need to be added. SPORT 1450 1250 400 DOCUMENTARY SCI-FI 500 DRAMA