Final answer:
The total surface area of the wooden board to be stained is calculated by adding up the areas of all faces of the rectangular prism. This can be found using the formula 2lw + 2lh + 2wh where l is length, w is width and h is height.
Step-by-step explanation:
To find the total surface area that Brianna will stain on her wooden board, we need to look at all faces of the rectangular prism. There are six faces in a rectangular prism; a pair of length x width, another pair of length x height, and the last pair of width x height.
Let's say the length of the board is 'l', the width is 'w' and the height is 'h'. We calculate the surface area by adding up the areas of all of the faces.
The calculation is: 2lw + 2lh + 2wh. This will give us the total surface area of the wooden board that will be stained.
Learn more about Surface Area