# Find the area of a sector of a ring

A ring sector is the part of a circle bounded by an outer and inner arc and two radii connecting the ends of the arcs to the center of the circle. To find the area, you need to know the radii and angle of the sector.

**Ring sector area**

**Ring sector angle α**

**Ring outer radius R**

**Ring inner radius r**

The formula for calculating the area of a sector of a ring: