Question

Your friend finds the surface area of the prism.

Is your friend correct? Explain your reasoning

Answer 1

Hint:

Step 1: The surface area of the prism $=2lw+2lh+2wh$

Step 2: Surface area $=2(5\times 3)+2(3\times 4)+2(4\times 5)$
Surface area $=2\left(15\right)+2\left(12\right)+2\left(20\right)$
Surface area $=(30+24+40)c{m}^2$
Surface area $=94c{m}^2$

Therefore, No, my friend is wrong, the area of the $3\times 5$ face is used $4$ times rather than just twice.