The roofing industry speaks of a "square" as meaning 100 square feet. So, if your contractor says your roof is about 9 squares, he means it will require about 900 square feet of materials in order to cover the surface area of your roof.
I just cheecked the web but I saw no such thing as a 900 square feet trailer. You may want a professional to take a look.Sorry I couldn't help you that much. :(
what is the cost of a roof per square foot
The [perfect] square of 900 is 810000
per roof square.
900 square inches = 0.694 square yards.
There are 144 square inches in one square foot. Therefore, 900 square inches is equal to 900/144 = 6.25 square feet.
99.7
Unless you have a flat roof, no; the surface area of the roof will be larger than the ground area of the building.
900 square feet = ~83.6 m2
There are 9 square feet in one square yard. Therefore, 900 square yards is equal to 900 x 9 = 8100 square feet.
When talking about the area of a roof, remember that it is not the same as the square footage of the structure. For example a 20 x 30' building with a 12" overhang and a 4/12 pitch will have 736 sq ft of roof vs only 600 sq ft of slab. One square of shingles covers 100 square feet. 15 year shingles come 3 bundles to a square. 25 year come 4 bundles to a square.