This cube lacks two circular areas due to drilling, but there are some areas inside the cube, which are two curved areas and two cylindrical bottom areas. By moving the two extra bottom circles inside the cube to the surface of the cube, a complete cube can be formed, and the calculation will be simplified, thus increasing the surface area of the cube by two cylindrical curved surfaces.

Calculate the surface area of the cube first: 40*40*6=9600 square centimeters.

Calculate the area of two cylindrical surfaces: π*4* 10*2=80π square centimeters? (π is approximately equal to 3. 14)

Therefore, the part area is 9600+80 π ≈ 9851.2cm2..

Calculate the surface area of the cube, then calculate the upper surface area of the circular hole, and then calculate the lateral area of the circular hole. Use the cubic surface area to add the round hole side area, and then subtract the two upper surface areas.

16* 16*6+6*3. 14* 16-3*3*3. 14*2

= 1536+30 1.44-56.52

= 1780.92

The length of the cut rectangle is 10× 2×π = 62.8 (cm), and the area of the original rectangle is (10× 4+62.8) × (10× 2) = 2056 square cm.