How to you express area of each square as monomial

The area of a rectangle (including squares) is defined as length times width or the equation:

A=l*w

However a square has the special property where length equals width which is represented by this equation:

l=w

So replace one of the variables with the other to get this new equation:

l*w=A

(w) * w=A

w^2=A

Often times for square the variable is represented as an s so:

s^2