If we cut a circular cake into three equal parts, then geometrically the three parts obtained after cutting the cake are
It can be observed that the cake will be cut into 3 parts as shown above figure.
The portion (or part) of the circular region enclosed by two radii and the corresponding arc is called a sector of the circle.
The radii for each sector will be the line along cut has been made. The corresponding arc will be the boundary of circular cake between 2 lines of cut for each piece. It is clear each cut piece of the cake is a sector.