Answer:
140
Step-by-step explanation:
The surface area of the figure is the sum of all the faces.
If we look at the middle three rectangles as one big rectangle, we see that the height is 8 cm and that the base is 15 cm. Therefore, the area of the rectangle is [tex]8\cdot15=120~\text{cm}^2[/tex].
The area of one of the two triangles is [tex]\frac{1}{2}\cdot 4\cdot 5=10[/tex], so the combined area of them is [tex]10\cdot2=20~\text{cm}^2.[/tex]
Adding these areas up, the total surface area is [tex]120+20=\boxed{140~\text{cm}^2.}[/tex]
