To find the surface area of the figure shown, Mia found the surface area of the two triangular prisms and the rectangular prism. From this, Mia subtracted 6 ft2. Did Mia make an error?
Mia should have subtracted 16 square feet.
Mia needs to subtract another 6 square feet.
Mia must calculate each triangle separately.
There is no error—Mia is correct.