<Polygon-2024-269>, hint
Let AD^BE=H, CF^AD=I, CF^BE=K
Since [ABCD]=[AFED] and [BCDE] =[BAFE] --->[ABH]=[DEH]
and let [HIK]=s [AHB]=x [DEKI]=x-s, [CDI]=y [AFKH]=y-s [EFK]=z [BCIH]=z-s
Since [ABCD]=AFED]<--> x+y-s+z=z-s+y+x-s Hence s=0
Thus AD, BE, CF concur at one point O.
Let OA=a, OB=b, OC=c, OD=d, OE=e, OF=f
AB+BC+CD=AF+FE+ED and BC+CD+DE=EF+FA+AB--->AB=DE
Similarly BC=EF CD=AF. [OAB]=[ODE]---> ab=de bc=ef, cd=af
Consider quadrilateral ABDE ab=de <---> a/e=d/b triangles AOE and DOB are similar
Hence ABDE is a parallelogram OA=OD, OB=OE
Thus O is the center of symmetry.
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