Answer:
The original dimensions of the building is 95 ft × 38 ft.
Step-by-step explanation:
Let the original length be 'l' and original width be 'w'.
Given:
Original length (l) =

Original width = 'w'.
So,

Now, as per question:
Length and width is increased by 7 ft.
So, new length (l') =

New width (w') =

New perimeter (P) = 266 ft
Perimeter is given as:

Therefore, original width = 38 ft.
Original length is,

Hence, the original dimensions of the building is 95 ft × 38 ft.