Find the surface area of triangular prism.

Solution:

We have:  Surface prism = A

A = 2 × 3 × 8 / 2 + 2 × 5 × 9 + 8 × 9

A = 24 + 90 + 72

A = 186 cm²

You can add up all the sides, so for the base, you'll get 8x3/2 but since you have 2 same base, you can just cancel out the /2. so the answer is 24. then add up the other sides, we have 2 9x5 rectangles, and a 8x9 side at the bottom. so just add 24 + 90 + 72, so the final answer should be 186 cm2