Hey GAMEMASTERX40!
The formula to find the area of a square is L^2, where L is the side length.
Therefore, to find the side length of square #1, we want to find the square root of x^2+4x+4.
We can factor this, since it’s a perfect square:
x^2+4x+4=(x+2)^2, the side of the square is x+2.
Therefore, the side length of square #3 is twice of this, or 2x+4.
The area of square #3 must be (2x+4)^2.
I hope this helped,
Gavin