The surface area of a triangular prism is \( S.A. = \text{Base Area} \) + \( (S_1 + S_2 + S_3) \), where \( S_1, S_2, \) and \( S_3 \) are the areas of the three rectangular lateral faces of the prism.
To be more specific, if we let the base of the triangular prism be a triangle with area \( A \) and the three sides of the triangle have lengths \( a, b, \) and \( c \), then the formula can be completed as follows:
The surface area of a triangular prism is \( S.A. = A + (S_1 + S_2 + S_3) \).
Here, \( A \) is the area of the triangular base, and \( S_1, S_2, \) and \( S_3 \) are the areas of the three rectangular faces formed by the height of the prism and each side of the triangle.