Square feet and feet are not interchangable. Square feet measures area, which is 2D, while feet measure distance, which is 1D. You can't convert the two.
A foot is a unit of distance. A square foot is a unit of area. The two units are therefore incompatible. A square foot is a square, one foot across by one foot down. It is flat. It does not describe...
You can't. A foot is a measure of length, a square foot is a measure of area. If you are asking how to find an area, search for "area of ______" then put in what shape you want the area of, like a...