Question

3 in
9 in
14 in
surface area = ____

Explanation:

Step1: Recall surface - area formula for rectangular prism

The formula for the surface area \(S\) of a rectangular prism is \(S = 2(ab+bc + ac)\), where \(a\), \(b\), and \(c\) are the lengths of the three sides. Here \(a = 3\) in, \(b=9\) in, and \(c = 14\) in.

Step2: Calculate \(ab\), \(bc\), and \(ac\)

\(ab=3\times9 = 27\) in², \(bc=9\times14 = 126\) in², \(ac=3\times14 = 42\) in².

Step3: Calculate \(ab + bc+ac\)

\(ab + bc + ac=27 + 126+42=195\) in².

Step4: Calculate the surface area

\(S = 2\times195=390\) in².

Answer:

390 in²