question\nfind the surface area of the rectangular prism.

Explanation:

Step1: Recall surface - area formula

The surface - area formula of a rectangular prism is $S = 2(ab+bc + ac)$, where $a$, $b$, and $c$ are the lengths of the three sides. Here, $a = 3$ km, $b = 2$ km, and $c = 1$ km.

Step2: Calculate $ab$

$ab=3\times2 = 6$ km²

Step3: Calculate $bc$

$bc = 2\times1=2$ km²

Step4: Calculate $ac$

$ac=3\times1 = 3$ km²

Step5: Substitute into formula

$S=2(6 + 2+3)$ $S=2\times11$ $S = 22$ km²

Answer:

$22$ km²