Alexis ordered an ice cream cake from Molly Moo Creamery. The box that it was packed in was a rectangular prism. The dimensions of the box are shown in the diagram.

7 in.

12.4 in.

9.1 in.

What is the total surface area of the box of in square inches?

1 answer

To find the total surface area of a rectangular prism (box), you can use the formula:

\[ \text{Surface Area} = 2(lw + lh + wh) \]

where \( l \) is the length, \( w \) is the width, and \( h \) is the height of the prism.

In your case, the dimensions of the box are:

  • Length (\( l \)) = 12.4 inches
  • Width (\( w \)) = 7 inches
  • Height (\( h \)) = 9.1 inches

Now, plug these dimensions into the formula:

  1. Calculate \( lw \): \[ lw = 12.4 \times 7 = 86.8 , \text{square inches} \]

  2. Calculate \( lh \): \[ lh = 12.4 \times 9.1 = 113.84 , \text{square inches} \]

  3. Calculate \( wh \): \[ wh = 7 \times 9.1 = 63.7 , \text{square inches} \]

  4. Now add these areas together: \[ lw + lh + wh = 86.8 + 113.84 + 63.7 = 264.34 , \text{square inches} \]

  5. Finally, multiply by 2 to find the total surface area: \[ \text{Surface Area} = 2 \times 264.34 = 528.68 , \text{square inches} \]

So, the total surface area of the box is \( \boxed{528.68} \) square inches.