To find the surface area of the box that needs to be decorated, we need to calculate the area of the surfaces that will be decorated. Since the bottom and the back of the box do not need to be decorated, we will only include the front, both sides, and the top in our calculation.
The dimensions of the box are:
- Length (front) = 27 cm
- Width = 20 cm
- Height = 20 cm
-
Calculate the area of the front:
Area_front = Length × Height
Area_front = 27 cm × 20 cm = 540 cm² -
Calculate the area of the two sides:
Area_side = Width × Height
Area_side = 20 cm × 20 cm = 400 cm²
Since there are two sides, we multiply by 2:
Area_sides = 2 × 400 cm² = 800 cm² -
Calculate the area of the top:
Area_top = Length × Width
Area_top = 27 cm × 20 cm = 540 cm² -
Total area to be decorated:
Total_area = Area_front + Area_sides + Area_top
Total_area = 540 cm² + 800 cm² + 540 cm² = 1,880 cm²
Thus, the surface area of the box that needs to be decorated is 1,880 cm².
Final Answer: 1,880 cm²