Question

1. 6 mm 5 mm 13 mm sa = 173

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. Here, $l = 13$ mm, $w = 5$ mm, and $h = 6$ mm.

Step2: Calculate $lw$

$lw=13\times5 = 65$ mm²

Step3: Calculate $lh$

$lh=13\times6 = 78$ mm²

Step4: Calculate $wh$

$wh=5\times6 = 30$ mm²

Step5: Calculate surface - area

$SA = 2(65 + 78+30)=2\times173 = 346$ mm²

Answer:

$346$ mm²