Finding a rectangle's area is one step. Finding the rectangle from its area and its perimeter is a search — because neither fact settles it alone, and the work is putting them together.
Kid stuck on one? You don’t just get the sheet.
The answer key prints on a separate page.
An area of 48 could be 1×48, 2×24, 3×16, 4×12 or 6×8. A perimeter of 28 could be any pair adding to 14. Each fact on its own leaves a list; only together do they leave a rectangle. That is the whole question, and it is why a child cannot start it the moment they finish reading it.
The route runs without algebra. Halve the perimeter and you have the sum of the two sides. List what multiplies to the area. The pair that also adds to the half-perimeter is the rectangle — and the answer key prints that reasoning rather than two numbers, because a child who found the wrong pair needs to see which check they skipped.