what happens to the surface area of a cube if each of its edges is doubled?
Surface area of original cube = 6a2 ... (1)
When the edge of the cube is doubled, the edge of the new cube becomes 2a.
So, Surface area of new cube = 6(2a)2 = 24a2 = 4(6a2)
Thus, if the edge of a cube is doubled, then its surface area becomes four times the original surface area.