Respuesta :

P=4*a, where P - perimeter, a - length of one side of the square.

if a=x+3 and P=48, then 4(x+3)=48;

x=9.

Answer: 9 units.

Well, since its a square, all sides are equal, and it has four sides! so, all we gotta do is divide the perimeter by four to get the measurement of every side, and to solve x(that is to assume that x is a side).

48/4=12

So, if x is a side, this means that it is twelve units!

However, if we are to assume that x is a angle, it will be ninety, as all right angles are ninety.