Answer:
bh + 3lw
Explanation:
A triangular prism is made up of two opposite rectangular surface, two opposite triangular surfaces and its rectangular base.
Area of a triangle =
bh
where b is its base, and h is the height.
Total surface area of the two triangular surfaces =
bh +
bh
= bh
Area of rectangle = lw
where l is the length and w its width.
The surface area of the rectangles = lw + lw + lw
= 3lw
Thus,
Total surface area for a triangular prism = bh + 3lw