Circular Sector

Circular Sector

Portion of a circle enclosed between two radii.


  • To calculate the area A in degrees: A = \(\dfrac{α}{360}\) × πr\(^{2}\)
  • To calculate the area A in radians: A = \(\dfrac{αr^{2}}{2}\)

secteur circulaire


For a sector whose angle α is 90° (or π2 in radians) and whose radius r measures 10 cm, we have:

  • In degrees: \( A = \dfrac{a}{360} × π r^{2}= \dfrac{90}{360} × 100π = 25π\).
  • In radians: \(A = \dfrac{αr^{2}}{2} = \dfrac{\dfrac{π}{2} × 10^{2}}{2} = 25π\).

Try Buzzmath activities for free

and see how the platform can help you.