Question 763978
Width = x
Length = x + 7
Right angled triangle.
Diagonal = Hypotenuse.
x^2 + (x + 7)^2 = 13^2
x^2 + x^2 + 14x + 49 = 169
      2x^2 + 14x - 120 = 0
      (2x - 10)(x + 12) = 0
x + 12 = 0
x + -12 (no answer)
2x - 10 = 0
      2x = 10
       x = 5.
So, Width = 5 inches
Length = 12 inches
Hope this helps.
:-)