7/12 = 0.5833... feet (approx).
If the radius of a circle is 80 inches, then the area of the circle is 139.6263 square feet. (rounded)
80
7 ft/ 80 inch so... 84 inch/80 inch 42 inch/ 40 inch 21 inch/20 inch
16" * 16" = 1.77777 square feet, so , 80 / 1.77777 = 45 tiles
80
I think one 80 lb. bag will cover about 4 square feet 1 inch thick
80 if the tiles are 12x12 - 12x12 is one square foot covering 80 you would need 80 tiles
There are 80 tenths-of-a-foot in 8 feet. But this measurement is rarely used. There are 800 tenths of an inch, also rarely used.
You'll need 90 of them because 80/(16/12 times 8/12) = 90
80*80 = 6400 square feet
(80x80)/144 = 6400/144 = 3200/72 = 1600/36 = 800/18 = 400/9 = 44 and 4/9 square feet