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.

GCSE Edexcel Circles, sectors and arcs - Edexcel Circumference of a circle The circumference of a circle is its outside edge, and is the same distance from the centre at every point along its length.

Yes, this is essentially the same equation used to find the circumference of a circle if θ is measured in radians (which it should be).