None, since there can be no conversion.
A cubit = 1.5 feet so 2.1 cubit feet is a measure of area in 2-dimensional space while a foot is a measure of length in 1-dimensional space. The two measure different things and, according to basic principles of dimensional analysis, any attempt at conversion from one to the other is fundamentally flawed.
Many.
1 cubit = 1.5 feet so 1 cubit feet is an area of 1.5 square feet.
1 cubit = 1.5 feet so 1 cubit foot is an area of 1.5 square feet.
512 feet squared
Square feet are a measure of area. A square is a flat thing with no vokume. Cubit feet don't exist. Cubic feet are a measure of volume. There is no way of expressing a volume in units of area.
There are 3 cubit feet in 1 cubit yard. Although irrelevant in this context, you may wish to know that 1 cubit = 1.5 feet = 0.5 yards.
1 cubit = 1.5 feet
Many.
1 cubit = 1.5 feet so 1 cubit feet is an area of 1.5 square feet.
1 cubit = 1.5 feet so 1 cubit foot is an area of 1.5 square feet.
512 feet squared
1 cubit = 1.5 feet so 27 cubit feet is an area of 40.5 square feet.
1 cubit = 1.5 frrt so 1.5 cubit feet = 2.25 square feet.
8 cubit feet = 12 square feet.
2000 square feet = 1333.33... (recurring) square feet.
One cubit = 1.5 feet so a cubit foot is a measure of area in 2-dimensional space. An area has no mass. You need to have a thickness before you can have a volume and therefore, a measure of mass.
If you meant "cubic yard," then there are 27 cubic feet in 1 cubic yard. If you meant "cubit yard," then there is no such measurement. However, one cubit is equal to 1/2 yard, which is equal to 1 and 1/2 feet.