Question 312484
The area of a square is the same as its perimeter. The measure of a side is (x – 4)units. What is the only possible value of x?

area square = side^2 = a^2
perimeter square = 4*side = 4a
a^2 = 4a
  a = 4
plug in (x-4) for a
  x - 4 = 4
  x = 8

(x-4)^2 = 4^2 = 16
4(x-4) = 4x - 16 = 32 - 16 = 16