Hi!
You don’t need to find any measurements because the question says “solve in terms of x.” So basically instead of putting numbers in your equations, you would put the expressions given to represent height and width (x and x + 3).
To solve the problem, you would use your regular formulas for finding the area and perimeter of a rectangle (A=l x w and P = sum of all four sides). Instead of using numbers put in the equations and simplify.
P = x + x + x + 3 + x + 3
= 4x + 6
A = lw
= (x)(x + 3)
= x^2 + 3
I think these solutions are right, haven’t dealt with these problems in a long time.