How to find the primeter of a rectangle when the area and lenthh is given?

Okay, this will take some thinking, especially since I do not know your figures that are already given. Okay lets let X = the perimeter since that is what we need to know. Now lets say that the length is 8 and the area is 56. Now we need to find the width to be able to find the perimeter. So, since we know that in order to find area use the formula for area of a rectangle which is length multiplied by width. So since we don't know the width we will have to work backwards by dividing the area by the length. ( L times W = A). So we will divide A by L to get W. If we did 56 divided by 8, we get 7. So now we know that the width is 8. You can check your work by plugging the numbers in. L times W = A . We said that L =8, W =7 and A= 54. Which works out because 8 times 7= 56. So now we have to find the perimeter. The formula for finding the perimeter of a rectangle is 2 times L + 2 times W = P. So we know that the length is 8 and the width is 7 right? So now we can dot he easy part. 8 times 2 + 7 times 2 = perimeter. That equals, 16 + 14. So the perimeter equals 30.