To find the surface area of a rectangular prism (like a textbook), you can use the formula:
\[ \text{Surface Area} = 2(lw + lh + wh) \]
where \( l \), \( w \), and \( h \) are the length, width, and height of the prism.
For the textbook dimensions provided:
- Length (\( l \)) = 14 in.
- Width (\( w \)) = 2 in.
- Height (\( h \)) = 9 in.
Now, plug these values into the formula:
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Calculate each area component:
- \( lw = 14 \times 2 = 28 \)
- \( lh = 14 \times 9 = 126 \)
- \( wh = 2 \times 9 = 18 \)
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Add these components together: \[ lw + lh + wh = 28 + 126 + 18 = 172 \]
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Now multiply by 2 to get the total surface area: \[ \text{Surface Area} = 2 \times 172 = 344 \text{ in.}^2 \]
Therefore, the surface area of the textbook is 344 in.².