sound like yu tri tu deskribe a rektangel with a half serkel on 1 end . . . thats NOT a trak feeld . . . me assume 2 strate sides at 7.1 & 1 at 3.2=14.2+3.2=21.3 . . . then add a half serkel with rad=1.6: its leng=pi*1.6, or bout 5.03 . . . rim leng=21.3+5.03=26.33