Question

3 identical rectangular prisms are stacked on the top of each other as shown in the given diagram. What will the combined surface area of the structure formed be?

• A. 324 sq units
  
• B. 364 sq units
  
• C. 264 sq units
  
• D. 332 sq units
  

Answer 1

The correct option is D 332 sq units



Let l, w, and h be the corresponding length, width, and height of one rectangular prism as shown above.
To find the total surface area of the structure, let's combine all three rectangular prisms into a single structure with dimensions shown below.


Here, length (l) = 10 units, width (w) = 4 units, and height (H) = 9 units.
Therefore, the total surface area $=2\times (lw+wH+Hl)$
$=2\times (10\times 4+4\times 9+9\times 10)$
$=2\times (40+36+90)$
$=2\times 166$
$=332$ sq units