oktogon=8 sides... me assume yu meen REGULAR oktogon...all sides the same leng... regular oktogon is symmetrik bout all sorts av waes, so... wide=hite... wen me make it with side leng=1, me get hite=2.414214... tu get wide=18ft...fakter=18/2.414214=7.455842771 ft side leng... this gave me hite=wide=17.9939... & rim leng=59.64, & area=268.407212