Answer:
The perimeter of the TV = 8 feet
Step-by-step explanation:
The keywords in this question are "similar in shape". This means that the dimensions of the two TVs are equivalent, but they are not the same.
TV in family room = 3 feet wide, 5 feet long = 3/5
TV in bedroom = 1.5 feet wide, x feet long = 1.5/x
Since the TVs are similar:

Therefore the TV in bedroom is 1.5 feet long and 2.5 feet wide.
Perimeter of a TV = perimeter of a rectangle
Perimeter of a rectangle = (2 × Length) + (2 × width)
Perimeter = ( 2 × 1.5) + ( 2 × 2.5)
= 3 + 5 = 8 feet