what is the surface area of a rectangular prism that has a height of 5cm a width of 10cm and a depth of 4cm

2 (5*10) + 2 (10*4) + 2 (5*4) =

2 (50) + 2 (40) + 2 (20) = 100+80+40=

220 cm^2

I found the answer by finding the areas of the 3 different sides, multiplying each area by 2 since each side has another side that is equal on a rectangular prism, then adding all of them together.