Solution: ① Take point A and point B on a larger arc and connect AB, so that the line segment AB passes through three arcs at the same time, and then make it the middle vertical line CD of AB;

(2) connecting DE, and making the intersection of DE and the middle vertical line of point O "CD, then this point is the center of the circle where $\widehat{DE}$ is located;

(3) Connect GF as the intersection point CD of the perpendicular line between GF and point O', then O' is the center of the middle arc;

(4) Connect BC so that BC intersects with the perpendicular of point O, and CD, then O is the center of the larger arc.

As can be seen from the figure, the radius of the top arc is the largest and the radius of the bottom arc is the smallest.