Answer: 337.32 cm²
There are two ways to solve your problem.
[Way #1]
To find the surface area, we will find the area of the six sides. This will be three pairs of congruent rectangles (six total).
-> See attached
-> In summary, find the area of all the sides and add them together
[Way #2]
We can use the formula below to solve in one step. Let 7.2 cm be the width, 10.3 cm be the length, and 5.4 cm be the height.
-> This formula is doing exactly what way #1 does, but in fewer steps.
A = 2(wl + hl + hw)
A = 2((7.2 cm)(10.3 cm) + (5.4 cm)(10.3 cm) + (5.4 cm)(7.2 cm))
A = 2(74.16 cm + 55.62 cm + 38.88 cm)
A = 337.32 cm²