The perimeter is 29cm, and the width is 6.5.
Explanation: When given just the area and a side length of a rectangle, the formula to discover the perimeter is P=2l+2(A/l). In this case, you would plug your numbers in; P=2(8)+2(52/8) and then solve, which would leave you with 29cm. To find the length, since you already know one side, and you know that opposite sides of a rectangle must be equal, you can subtract both of those sides from the perimeter (29-(8+8)) which would leave you with 13. From there, since you know the other two sides must also be equal, you would divide 13 by two to figure out your last two sides. 13/2=6.5.