Question

the rectangular prism below has a length of 18 inches, a width of 24 inches, and a height of 12 inches. what is the surface area of the prism? 1,440 square inches 1,584 square inches 1,872 square inches 2,160 square inches

Explanation:

Step1: Recall surface - area formula

The surface - area formula for a rectangular prism is $SA = 2(lw+lh + wh)$, where $l$ is length, $w$ is width, and $h$ is height.

Step2: Substitute values

Given $l = 18$, $w = 24$, and $h = 12$. Substitute into the formula:
\[

$$\begin{align*} SA&=2(18\times24 + 18\times12+24\times12)\\ &=2(432+216 + 288)\\ &=2(936)\\ &=1872 \end{align*}$$

\]

Answer:

1,872 square inches