FInd the height of the box by dividing the volume by 7 x 5 ( length x width)
Height = 105 / 35
Height = 3cm
There are 6 sides to a box.
Surface area = 2 x length x width + 2 x length x height + 2 times height x width
SA = 2*7*5 + 2*7*3 + 2*5*3
SA = 70 + 42 + 30
SA = 142 cm^2
