If the breadth is x and the length is 2x, we know that the perimeter is 2x + x + 2x + x = 48. Which means 6x = 48 so x = 8
Now we can find the surface area because the length is 2x so we substitute the 8 in and we get the length to be 16, and the breadth to be 8 (because breadth = x and x = 8)
Total area = length x width = 16 x 8 = 128
