Final answer:
The length of an edge of a cube with a surface area of 72 cm² is approximately 3.46 cm.
Step-by-step explanation:
The surface area of a cube is given by the formula SA = 6s², where s is the length of one side of the cube. We are given that the surface area of the cube is 72 cm². Setting up the equation, we have 6s² = 72. Solving for s, we divide both sides of the equation by 6 and take the square root, giving us s = √(72/6). Simplifying, we get s = √12, which is approximately 3.46 cm.