To find the surface area of a rectangular prism (which is the shape of the textbook), you can use the formula for the surface area \( SA \):
\[ SA = 2(lw + lh + wh) \]
where \( l \) is the length, \( w \) is the width, and \( h \) is the height.
For the textbook dimensions:
- \( l = 14 , \text{in} \)
- \( w = 2 , \text{in} \)
- \( h = 9 , \text{in} \)
Now, substitute the values into the formula:
\[ SA = 2(14 \times 2 + 14 \times 9 + 2 \times 9) \]
Calculating the individual areas:
- \( 14 \times 2 = 28 \)
- \( 14 \times 9 = 126 \)
- \( 2 \times 9 = 18 \)
Now, adding these products together:
\[ 28 + 126 + 18 = 172 \]
Now, multiply by 2:
\[ SA = 2 \times 172 = 344 , \text{in}^2 \]
Therefore, the surface area of the textbook is \( 344 , \text{in}^2 \), or \( 344 , \text{in. squared} \).
The correct response is:
344 in.² or 344 in. squared.
1 answer