Step-by-step explanation:
the opposite angles are always same.
It's the one on the bottom left that says 5ft and 3ft, they're the same shape and ratio just turned around. It's also the square that says 6ft and 10ft because its only two times bigger than the original and has similar proportions.
Answer:
For number 3 the answer is -4
That would be Nets 1, 4 and 5.