A rectangular room that has two walls that are 10 feet long and two walls that are 16 feet long contains exactly 160 square feet. A square foot measures the area of a space and is found by multiplying the length by the width of a four-sided space.
Rooms that have more exotic shapes have different formulas for determining the number of square feet they contain. Most often these spaces are broken down into simpler shapes to find their total area. For example, the floor plan of an eight-sided room may be broken up into four triangles and one central rectangle to determine its total square footage with ease.