Question

what is the surface area of a triangular prism?

Answer 1

bh + (S1+ S2 + S3)H

Answer 2

Triangular based prism

Base shape: Triangle: base 'b', height 'h', and sides S1, S2 and S3
Area of base: ½b×h
Perimeter of base: S1+ S2 + S3

So, the formula is
Surface area= 2*(area of base) + (base perimeter)*(prism height)
Or
Surface area = bh + (S1+ S2 + S3)H
where
b=Triangle base
h=Triangle height
S1=Side 1 of triangle
S2=Side 2 of triangle
S3=Side 3 of triangle
H=Prism height