˿

Sector, segment and arc - Higher only – WJECParts of a circle

Sometimes we need to know how to calculate values for specific sections of a circle. These can include arc lengths, the area and perimeter of sectors and the area of segments.

Part of MathsGeometry and Measure

Parts of a circle

Do you remember some key parts of a circle?

  • an arc is a section of the circumference of the circle
  • a sector is an area enclosed by two radii and an arc
  • a chord is a straight line connecting two points on the circumference of a circle
  • a segment is a section formed between an arc and a chord
A diagram showing key parts of circle, labelled chord, segment, sector and arc.