The surface area (S.A) of a triangular prism can be calculated using the formula:
\[ S.A = \text{Base Area} + (S_1 + S_2 + S_3) \]
Where:
- The Base Area is the area of the triangular base of the prism.
- \( S_1, S_2, \) and \( S_3 \) are the areas of the three rectangular faces of the prism.
So, to fill in the blanks:
S.A = Base Area + ( S₁ + S₂ + S₃ )