6x9=54.
Multiply the two dimensions to get the area. The calculation will give you 54 square feet.
At minimum, 427. Depending on the exact geometry, you might need more than that.
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 sq m
The answer depends on the units used for 6*9 and since you have not bothered to share that crucial bit of information, I cannot provide a more useful answer.
6 If we assume that the pavers are 6 inches by 9 inches, then its area is 6*9 = 54 square inches. 54 sq.in. = 54/144 = 0.375 square feet each. 36 sq.ft / 0.375 sq.ft. = 96 pavers (nett). In practice you may need a few extra to allow for breakages, out-of- squareness, etc.
Multiply the two numbers together 6 ins x 9 ins = 54 sq. ins. ( Square inches ) Done!!!!!
1/5 cubic feet of airspace
54 sq. in.
6x9=54
In theory the answer is 240 tiles but this assumes that the area is "well behaved" and, if not, that you are prepared to use all the offcuts to fill bits in mosaic-style. A shape which in 17 inches wide, for example, will require a lot more pavers.