Question

First, find the surface area of the yellow prism

Answer 1

Check the picture below.  Notice, we're skipping the bottom part of it.

$\begin{array}{llll} front&4\cdot 3&=&12\\ back&4\cdot 3&=&12\\ right&3\cdot 4&=&12\\ left&3\cdot 4&=&12\\ top&3\cdot 3&=&9\\ \cline{1-4} total&&&57 \end{array}$