The meaning of a sector is a figure surrounded by an arc and two radii passing through both ends of the arc, which is called a sector. Sector is an important figure related to the circle, and its area is related to the central angle (vertex angle) and radius of the circle. The area of a sector with a central angle of n and a radius of r is n/360 * π r 2. If the vertex angle is in radians, it can be simplified. ...