A sector is an area formed between the two segments also called as radii, which meets at the center of the circle. The angle between the two radii is called as the angle of surface and is used to find the radius of the sector. An arc is a part of the circumference of the circle. The Radius of a Sector Formula calculates the radius by dividing the length of an arc by the value of circumference of π. The Link below the formula can be used to calculate the radius of sector within seconds.