roof pitch factor 2

https://wiki-fusion.win/index.php/How_a_Roof_Area_Calculator_Simplifies_Your_Roofing_Project

When you're figuring out how much roofing material to buy, the roof pitch factor is your best friend. It's a simple multiplier that adjusts your roof's footprint to account for its slope. For instance, a flat roof might have a factor of 1, but a steep 12/12 pitch could bump it up to about 1.414. This number saves you from ordering too little—or paying for way too much.