Answer:
Length is 10
Width is 8
Explanation:
The formula for the perimeter of a rectangle is:

We are told that the length l is 2 more than twice the width w. In other words:

Also, we are given that the perimeter is 28. Therefore:

Distribute:

Combine like terms:

Subtract 4 from both sides:

Divide by 6:

So, the width is 4.
And the length is 2 more than twice the width. Thus:

The length is 10.
And we are done :)