To find the surface area of the triangular prism, we need to find the area of each of the 5 faces and then add them together.
1. The two rectangular faces on the sides have an area of length x width. Since the length is 9 cm and the width is 5 cm, the area for each rectangular face is 9 cm x 5 cm = 45 cm2.
2. The two triangular faces on the top and bottom have an area of (1/2) x base x height. The base is 9 cm and the height is 12 cm, so the area for each triangular face is (1/2) x 9 cm x 12 cm = 54 cm2.
3. The middle rectangular face has an area of 5 cm x 9 cm = 45 cm2.
Now, add up the areas of all 5 faces:
2(45 cm2) (rectangular faces) + 2(54 cm2) (triangular faces) + 45 cm2 (middle face) = 90 cm2 + 108 cm2 + 45 cm2 = 243 cm2
Therefore, the surface area of the triangular prism is 243 cm2.