The perimeter of the outside edge of the frame would be 42in. Considering that the frame adds an extra inch and a half to the rectangle on all sides, you would use the formula P=2(l+w). P is perimeter which is what your solving. This would be solved by first adding 1.5 to 8 to get 9.5 and plugging ll.5 for length and 9.5 for the height. You would get 21, and multiplying 21 by 2 gives you 42.
