Goes +3
18, 21, 24, 27, 30
The answer to this is 5√2
A triangular prism<span> has 5 faces, 3 being rectangular and 2 being </span>triangular<span>. The </span>area<span> of the rectangular faces can be found by multiply the base and height lengths together. The </span>area<span> of the </span>triangular<span> faces can be found by multiplying the base and height and dividing by 2.</span>