Final answer:
The correct answer is option C, (9, 12, 15), as 9^2 + 12^2 is not equal to 15^2.
Step-by-step explanation:
The Pythagorean theorem states that for any right triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. Using this theorem, we can determine which of the given options is not a Pythagorean triple.
To do this, we can calculate the square of the length of the hypotenuse for each option and check if it is equal to the sum of the squares of the other two sides. The correct answer is option C, (9, 12, 15), as 9^2 + 12^2 is not equal to 15^2.