If the height of a cuboid is 40 cm and its cross section is a cube, if the height is increased by 4 cm, the surface area will be increased by 80 square cm, and the original surface area will be calculated

If the height of a cuboid is 40 cm and its cross section is a cube, if the height is increased by 4 cm, the surface area will be increased by 80 square cm, and the original surface area will be calculated

What is the perimeter of the base of the cuboid
80 △ 4 = 20 (CM)
What is the length and width of a cuboid
20 △ 4 = 5 (CM)
What is the surface area of a cuboid
(5 × 5 + 5 × 40 + 5 × 40) × 2 = 850 (cm2)