Find the surface area of a textbook that is 2 in. × 14 in. × 9 in.

Question

(1 point)
Responses

172 in.2
172 in. squared

50 in.2
50 in. squared

252 in.2
252 in. squared

344 in.2

Answer 1

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 $l$ is the length, $w$ is the width, and $h$ is the height.

Given the dimensions of the textbook:

• Length (l) = 14 in.
• Width (w) = 2 in.
• Height (h) = 9 in.

Now, we can calculate each of the areas:

1. $lw=14\times 2=28$
2. $lh=14\times 9=126$
3. $wh=2\times 9=18$

Now, substitute these values into the surface area formula:

$$\text{Surface Area}=2(28+126+18)$$

Now calculate the sum inside the parentheses:

$$28+126+18=172$$

Now, multiply by 2:

$$\text{Surface Area}=2\times 172=344$$

Therefore, the surface area of the textbook is 344 in².

The correct response is:

344 in.²