It's true. That's how parallelograms are defined. Here's a diagram to show you what the question means. The opposite sides are parallel and there are 2 sets of parallel lines.
29/40 as a decimal would be .725 because you would have to divide 29 by 40 to get the answer.
I would actually use division. So divide 56 by 8, and you'll get 7.
Or you can multiply 7 times 8 and get 56.
Hope this helps!
♤MidnightQueen