But this has been exacerbated by human activities which have led to: 1) an increase in greenhouse gas emissions that causes heat to remain trapped within the troposphere, and 2) a decrease in ozone in the stratosphere, causing less sunlight to be absorbed by the ozone layer, resulting in a cooling of the stratosphere.
When measuring for floor tile the rule is: Length x Width + Waste = Amount Needed. Waste Factor will vary based upon tile size, layout, configuration of room, patterns, etc. Typical waste factor is about 10%. Add 15% for tile being installed diagonally or for a room with lots of jogs and corners.
Then, add the two planes together to derive the total square footage of the roof: 1  Plane 1: 120' x 100' = 12,000 sq. ft. 2  Plane 2: 120' x 100' = 12,000 sq. ft. 3  Plane 1 + Plane 2 = 24,000 sq. ft. for the total square footage of the roof. Roof surfaces are measured in squares. A square is an area of roof which measures 100 square feet. To determine the number of squares on the gable roof above, simply divide its total of 24,000 square feet by 100. The result is 240, and this means you would need 240 squares of shingles to cover that roof.