The term 'PART OF A CARDIOID FIGURE' can be summarized as an ARC, which is a three-letter word. An ARC is a curved line that forms part of the circumference of a circle or other shape. In mathematics, a cardioid figure is a plane curve generated by the locus of points on a circle that are equidistant from a fixed point on the circumference and from a fixed line not containing the center. The ARC is one of the parts of this figure.