For thousands of years, mathematicians noticed something magical: if you divide ANY circle's circumference by its diameter, you ALWAYS get the same number - π (pi) = 3.14159... This single number unlocks both the distance around a circle AND the space inside it!
This introduction covers The Most Famous Number in Maths within Circumference & Area of Circles for GCSE Mathematics. Revise Circumference & Area of Circles in Geometry & Measures for GCSE Mathematics with 11 exam-style questions and 7 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 1 of 10 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Circumference & Area of Circles
A circle has radius r. Which pair of formulas gives the correct circumference C and area A?
Explain why the circumference of a circle is measured in cm (or other length units) but the area is measured in cm² (square units).
Quick recall flashcards
Circumference
C = πd or C = 2πr
Area of Circle
A = πr²