### Formulas

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