Formulas
- To calculate the area A in degrees: A = \(\dfrac{α}{360}\) × πr\(^{2}\)
- To calculate the area A in radians: A = \(\dfrac{αr^{2}}{2}\)
Examples
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: \(A = \dfrac{αr^{2}}{2} = \dfrac{\dfrac{π}{2} × 10^{2}}{2} = 25π\).