Answer: Deductive reasoning
Step-by-step explanation:
The conclusion that the perimeter of the garden is 48 feet, based on knowing that one side of the square garden is 12 feet, is an example of **deductive reasoning**.
This is because you are applying a general rule (the formula for the perimeter of a square, \( P = 4 \times \text{side length} \)) to a specific case to reach a logical conclusion.