Question

Finding the surface area

Answer 1

So hmm notice the picture below

the triangular prism, is really just 3 rectangles and 2 triangles, stacked up to each other at the edges

now, just get the area of the triangles and the rectangles, and add them up, and that's the surface area of the triangular prism

now, what's the length "x"?  well  $\bf x^2=5^2+7^2\implies x=\sqrt{25+49}\implies x=\sqrt{74}$