Question

find the surface area of the rectangular prism. answer attempt 1 out of 2

Explanation:

Step1: Recall surface - area formula

The surface - area formula of a rectangular prism is $SA = 2(lw+lh + wh)$, where $l$ is the length, $w$ is the width, and $h$ is the height. Let $l = 4m$, $w = 3m$, and $h = 7m$.

Step2: Calculate $lw$

$lw=4\times3 = 12m^{2}$

Step3: Calculate $lh$

$lh = 4\times7=28m^{2}$

Step4: Calculate $wh$

$wh=3\times7 = 21m^{2}$

Step5: Substitute into formula

$SA=2(12 + 28+21)$

Step6: Simplify the sum inside the parentheses

$12 + 28+21=61m^{2}$

Step7: Multiply by 2

$SA = 2\times61=122m^{2}$

Answer:

$122m^{2}$