Question

1. what is the surface area of a cube, in square inches, if the length of one side of the cube is 3 inches?

9 in²
21 in²
27 in²
54 in²

Explanation:

Step1: Find the area of one face

The area of one face of a cube is \(s^2\) (where \(s\) is the side - length). Given \(s = 3\) inches, so the area of one face is \(3\times3=9\) \(in^{2}\).

Step2: Calculate the surface area of the cube

A cube has 6 faces. The surface area formula of a cube is \(SA = 6s^{2}\). Substitute \(s = 3\) into the formula: \(SA=6\times3^{2}=6\times9 = 54\) \(in^{2}\).

Answer:

\(54\space in^{2}\) (the fourth option)