Hey there!
Surface area is comparable to area of a shape, like a rectangle or square, but it's for a rectangular prism, which is a 3D shape. Therefore, we have an entirely different formula. It gives us the sum of the areas of all the faces- so instead of finding one area for one shape, we find all the areas for a 3D shape (a rectangular prism is made of rectangles).
We use the formula:
2(lw + wh + lh)
So, if our length was 1, width was 2, and height was 3, we'd have:
2(1*2 + 2*3 + 1*3) =
2(2 + 6 + 3) =
2(8 + 3) =
2(11) =
22 units squared.
Hope this helps!
