To find the surface area of a rectangular prism, we need to find the area of each face and then add them all together.
The textbook has six faces - a top face, a bottom face, a front face, a back face, a left face, and a right face.
The top and bottom faces are both rectangles with dimensions 2 in. and 9 in., so their areas are (2 in.)(9 in.) = 18 in² each.
The front and back faces are both rectangles with dimensions 14 in. and 9 in., so their areas are (14 in.)(9 in.) = 126 in² each.
The left and right faces are both rectangles with dimensions 2 in. and 14 in., so their areas are (2 in.)(14 in.) = 28 in² each.
Adding up all the areas, we have:
18 in² + 18 in² + 126 in² + 126 in² + 28 in² + 28 in² = 344 in².
Therefore, the surface area of the textbook is 344 square inches.
Find the surface area of a textbook that is 2 in. × 14 in. × 9 in.
1 answer