The surface area of a triangular prism can be expressed as:
\[ \text{S.A.} = (B) + (S_1 + S_2 + S_3) \]
Where:
- \( B \) is the area of the triangular base,
- \( S_1, S_2, S_3 \) are the areas of the three rectangular lateral faces.
So, the complete formula would be:
\[ \text{S.A.} = B + (S_1 + S_2 + S_3) \]