Answer:
3,216 cm²
Explanation:
The question is asking the surface area of a rectangular prism with the given dimension. That area is the sum of the areas of the 6 faces of the prism. Since opposite faces have the same area, we only need to compute 3 areas, then double the sum of those:
S = 2(LW +LH +WH)
This can be made a little easier to compute by some factoring:
S = 2(LW +H(L +W))
It does not matter which dimensions are designated length (L), width (W), or height (H).
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S = 2((24 cm)(54 cm) +(4 cm)(24 cm +54 cm))
= 2(1296 +4(78)) cm² = 2(1608) cm²
S = 3216 cm²
The surface area of Emma's rectangular box is 3216 square centimeters.