Question

a box measures 8 inches × 3 inches × 10 inches. what is the surface area of the box, in inches²?

Explanation:

Step1: Recall surface - area formula

The surface - area formula for a rectangular prism (box) is $SA = 2(lw+lh + wh)$, where $l$ is the length, $w$ is the width, and $h$ is the height. Here, $l = 8$ inches, $w = 3$ inches, and $h = 10$ inches.

Step2: Calculate $lw$

$lw=8\times3 = 24$

Step3: Calculate $lh$

$lh=8\times10 = 80$

Step4: Calculate $wh$

$wh=3\times10 = 30$

Step5: Calculate $lw+lh + wh$

$lw+lh + wh=24 + 80+30=134$

Step6: Calculate the surface area

$SA = 2\times134=268$

Answer:

268