Written below: d equals C divided by pi., The circumference of a circle is given by the formula 𝑪 = π𝒅. The diameter has been multiplied by π to give the circumference.

It is derived simply, by dividing the circumference of a circle by its diameter, or π = C/d, but the result is a never-ending "irrational" number: 3.14159265.

Pi is the ratio of the circumference of a circle to its diameter, which is approximately 3.14. Pi is one of the most famous symbols in mathematics and has many important applications in physics ...

Learn about the definition of pi in relation to a circle with this BBC Bitesize Maths article. For students between the ages of 11 and 14.