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

GCSE; OCR; Circles, sectors and arcs - OCR Arc length. Circles are 2D shapes with one side and no corners. The circumference is always the same distance from the centre - the radius.