Question

Each edge of a right triangular prism is 8 inches in length. What is the surface area of the right triangular prism?

Answer 1

Check the picture below.

since each edge is 8 inches, that simply means the right-triangle has a base of 8 and a height/altitude of 8 as well.

and since the triangular prism is really just two triangles and 3 rectangles, as you see there, we can simply get the area of each figure and sum them up, and that's the surface area of the prism.

$\bf \stackrel{\textit{area of the two triangles}}{2\left[ \cfrac{1}{2}(\stackrel{base}{8})(\stackrel{height}{8}) \right]}~+~\stackrel{\textit{area of the 3 rectangles}}{3(8\cdot 8)}\implies 64+192\implies 256$