so the trapezoidal prism is really 4 rectangles and 2 isosceles trapezoids.
so we can simply get the area of each of those shapes and sum them up and that's the area of the prism.
[tex]\bf \stackrel{\stackrel{\textit{front and back}}{\textit{trapezoids}}}{2\left[ \cfrac{6(4+12)}{2} \right]}+\stackrel{\stackrel{\textit{left and right}}{\textit{rectangles}}}{2(6\cdot 6)}+\stackrel{\textit{top rectangle}}{(4\cdot 6)}+\stackrel{\textit{bottom rectangle}}{(6\cdot 12)} \\\\\\ 6(16)+72+24+72\implies 96+168\implies 264[/tex]
