If  each side of a cube is tripled , then the percentage change in the surface area is:

800%

Surface area of cube = 6a²

After triipling each side of the cube

new surface area = 6 (3a)²

                            = 6 (9a²)

                            = 9 (actual surface area)

Surface area ⇒ Old : New = 1 :  9

Increased percentage = \(\frac{8}{1}\) × 100 = 800%