Question 1020266
If we call the width, x, then the length is x + 3.
We can apply the Pythagorean Theorem and write
x^2 + (x+3)^2 = 15^2
If you work that out, you'll find that the width
x = 9 inches
and
length x+3 = 12 inches
It's a 9 x 12.