Question 655350
you are given: the diameter of a circle is {{{(x+2)}}} units 

you need to  express the area of the square in the figure as a polynomial

as you know, the area of the square is {{{A=a^2}}} where {{{a}}} is the side of the square
if you take a close look at your picture, you will see that {{{a=(x+2)}}} units

so,the area of the square will be:

 {{{A=a^2units^2}}}

 {{{A=(x+2)^2units^2}}}

 {{{A=(x^2+4x+4)units^2}}}

so, your answer is: {{{(x^2+4x+4)units^2}}}