What is an equation for the perimeter of a square, p, as a function of its area, a?

Let side of square is x.
So we can say area of square is = (side) * (side)
So we can say area =
But as given area is a.
So we can write

Now we can find value of x as
.......................................................(i)

In general perimeter of square = 4 * side
SO the perimeter will be =
But is given perimeter is p.
So we can write
 

Now we can place value of x in this

There is no question, there is just the answer.