Three identical cubes are used to form a cuboid. The surface area of the cuboid is 84dm2. The surface area of the original cube is 84dm2______ dm2．

Three identical cubes are used to form a cuboid. The surface area of the cuboid is 84dm2. The surface area of the original cube is 84dm2______ dm2．

A: the surface area of a cube is 36 square decimeters

When two identical cubes are put together into a cuboid, the surface area is reduced by 24cm2, and the surface area of this cuboid is______ cm2．

The surface area of a small cube is: 24 △ 2 = 12 (square centimeter), the surface area of a cuboid is: (12-2) × 12, = 10 × 12, = 120 (square centimeter); answer: the surface area of a cuboid is 120 square centimeter. So the answer is: 120

The surface area of the cuboid is less than the sum of the two cuboids;
Is it right or wrong

Right! Because——
The area of two faces of the original cube is reduced by 2 & # 178; × 2 = 8dm & # 178;

Three identical cubes are used to form a cuboid. The surface area of the cuboid is 70dm & # 178; M. the original surface area of a cuboid is () DM
.
We need the formula!

Examples of answers:
After spelling out, there are 14 facets (cube), so each facet is: 70 △ 14 = 5 (square centimeter)
So, the surface area of a cube is: 5 × 6 = 30 (square centimeter)