Final answer:
Without the length of the third side of the garden, which is assumed to be triangular, we cannot calculate the precise perimeter. If all sides are equal, the perimeter would be 36 inches.
Step-by-step explanation:
If the two legs of the triangle are 12 inches each, the perimeter of the garden can be calculated by adding the lengths of all three sides. However, we need the length of the third side to determine the full perimeter. As the question only provides the lengths of two sides, we cannot definitively calculate the perimeter. If we assume the garden is triangular and the third side is also 12 inches, then the perimeter would be 36 inches, but this is purely speculative without more information.