Dimensional Formula is a standardized method to express the Physical quantities in terms of basic quantities as chosen in the SI system of measurement. These are denoted with symbols in square brackets []

The seven standards as per SI are
1) Mass
2) Length
3) Time
4) Electric Current [A]
5) Thermodynamical Temperature [K]
6) Luminous Intensity [Cd]
7) Amount of Substance [mol]

Area of Square (A)

Area of Square refers to the number of square units required to fill the square is called the area of square. Area is a derived physical quantity. A square metre is the area of a square whose each sides are 1 metre.

Area of the square = side × side  
So,
Area of the square = L × L=L²

Hence, Dimensional formula for Area of Square  =M⁰L²T⁰