Curriculum
Course: Mathematics — First Preparatory
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Curriculum

Mathematics — First Preparatory

Text lesson

Pie Charts

Mathematics — First Preparatory

Pie Charts

Worked examples

Worked examples

Comparison aspectMain ideaKeywords
Example 1
  • 40 pupils chose their favourite fruit: apples 12
  • bananas 8
  • oranges 20. Find the sector angle for each fruit
pupilschosefavouritefruit
SolutionThe total is 40. The apple angle = 12 ÷ 40 × 360 = 108°. The banana angle = 8 ÷ 40 × 360 = 72°. The orange angle = 20 ÷ 40 × 360 = 180°. Check: 108 + 72 + 180 = 360totalappleanglebanana
Example 2
  • In a pie chart whose data total 240
  • a sector has an angle of 90°. What value does the sector represent?
chartwhosedatatotal
SolutionThe value = 90 ÷ 360 × 240 = 60value
Example 3
  • The means of travel to work of 200 people were: 35% by bus
  • 25% by car
  • and 40% on foot. Find the sector angles
meanstravelworkpeople
SolutionThe bus angle = 35 × 3.6 = 126°. The car angle = 25 × 3.6 = 90°. The walking angle = 40 × 3.6 = 144°. Their sum is 126 + 90 + 144 = 360anglewalking
Comparison aspectMain ideaKeywords
Example 4
  • In a pie chart of the data of 300 pupils
  • a sector has an angle of 54°. How many pupils does this sector represent?
chartdatapupilssector
SolutionThe number of pupils = 54 ÷ 360 × 300 = 45 pupilsnumberpupils
Example 5 (the hardest)
  • A family’s monthly budget is 1800 pounds: food 600
  • rent 540
  • transport 360 and other expenses 300. Find the angle of each sector
familymonthlybudget1800
SolutionThe total budget = 600 + 540 + 360 + 300 = 1800. The food angle = 600 ÷ 1800 × 360 = 120°. The rent angle = 540 ÷ 1800 × 360 = 108°. The transport angle = 360 ÷ 1800 × 360 = 72°. The other expenses angle = 300 ÷ 1800 × 360 = 60°. Check: 120 + 108 + 72 + 60 = 360totalbudget1800food
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