Sheet № 183 · Foundation + Higher · AQA · Edexcel · OCR
Drawing Pie Charts –
Pie charts are a popular way to display categorical data and appear frequently on Foundation and Higher GCSE Maths papers across AQA, Edexcel and OCR. You need to be able to calculate the angle for each sector, draw a pie chart using a protractor, and read information from existing pie charts. These are reliable marks if you follow the me
§Key definitions
Question:
A survey asks 60 pupils their favourite sport. Football: 24, Tennis: 12, Swimming: 15, Other: 9. Draw a pie chart.
Answer:
Angles are Football 144, Tennis 72, Swimming 90, Other 54.
(a)
Frequency = (140 ÷ 360) × 180 = 25200 ÷ 360 = 70 people.
(b)
Angle = (45 ÷ 180) × 360 = 16200 ÷ 180 = 90 degrees.
Q1 (Foundation):
A class of 30 pupils chose their favourite colour: Red 10, Blue 8, Green 7, Yellow 5. Calculate the angle for each colour.
§Formulas to memorise
Angle for a category = (Frequency ÷ Total frequency) × 360
Frequency from a pie chart = (Angle ÷ 360) × Total frequency
Total = 60.
Worked example
A survey asks 60 pupils their favourite sport. Football: 24, Tennis: 12, Swimming: 15, Other: 9. Draw a pie chart.
Working:
⚠ Common mistakes
- ✗Angles not adding to 360. Always check your calculated angles sum to 360 degrees before drawing.
- ✗Inaccurate protractor use. Measure from the previous radius line, not from the starting line each time.
- ✗Comparing pie charts without using frequencies. A larger sector in one pie chart does not necessarily mean a larger frequency if the totals are different — always convert to actual numbers.
- ✗Rounding errors. If angles do not come out as whole numbers, round sensibly and adjust the last angle so the total is exactly 360.
✦ Exam tips
- →Show all angle calculations clearly — this earns method marks even if your drawing is slightly inaccurate.
- →If a question asks you to interpret two pie charts with different totals, you must calculate the actual frequencies before comparing.
- →Use a sharp pencil and ruler for radii. Neat, accurate sectors earn full marks.
- →For related data display, see reading and drawing bar charts. For key formulas, visit our GCSE Maths formulas page.