The answer will depend on the units used for 6X9. It also depends on the shape of the 225 square foot area: a circular area will require a lot more stones to be shaped and, therefore, a lot more wastage.
54
How many square feet will a ton of salt cover?
Tiles that are two feet on a side cover 4 square feet. 378 of them cover 1512 square feet.
A bundle of Shingles will cover roughly 33 square feet. A square of Shingles (3 Bundles) will cover 100 square feet.
That'll depend on what you're covering them with. A lot of square feet if you're covering them with 2000 pounds of silk or styrofoam, not many square feet if you're covering them with 2000 pounds of lead or stones or gold.
9 square feet.
240
it will cover 3 cubic feet, or 9 feet, I am not sure how many square feet
400 Square Feet.
190
1,440 square feet or 160 square yards.
200 square feet = 18.58 square meters.