Question

determine the surface area of a right prism with length 8 cm, width 5 cm, and height 20 mm. a) 600 cm² b) 480 cm² c) 80 cm² d) 132 cm²

Explanation:

Step1: Recall surface - area formula for rectangular prism

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.

Step2: Convert height to cm

Given height $h = 20\ mm=2\ cm$, length $l = 8\ cm$, and width $w = 5\ cm$.

Step3: Substitute values into the formula

$SA=2\times(8\times5 + 8\times2+5\times2)$
$=2\times(40 + 16+10)$
$=2\times(66)$
$ = 132\ cm^{2}$

Answer:

d) 132 cm²