Answer:
The surface area of the box is
.
Explanation:
Given that,
Ratio of the length to the width to the height of a rectangular box is

The sum of the length and width of box is

From the question,
Dimension of Rectangular box are
.
Let the side of rectangular box is x.
Now, Sum of length and width is


Then,

⇒

⇒

Here we get the dimensions are,

Then, surface Area of rectangular box =

=

=

=

Hence,
The surface area of the box is
.