The width of a rectangular slab of concrete is 16 m less than the length. The area is 80m^2The length is 20m. The width is 4in The perimeter of the rectangle is?

Ok, so
Given that:
The length is 20m.
The width is 4m.
The perimeter of the rectangle can be found if we sum:
20+20+4+4 = 48m.