Final answer:
C) Pythagoras.
Pythagoras is the pioneer of the Pythagorean theorem, a central concept in geometry concerning the relationship between the sides of a right-angled triangle.
Step-by-step explanation:
The person who pioneered the use of the Pythagorean theorem is C) Pythagoras. Pythagoras was a renowned Presocratic philosopher and is best known for the Pythagorean theorem, a fundamental principle in geometry that relates the lengths of the sides of a right-angled triangle. This theorem states that the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares on the other two sides. Although Pythagoras and his followers, the Pythagoreans, are credited with significant knowledge and contributions to mathematics, music, and astronomy, it's worth noting that Pythagoras may have learned, rather than independently discovered, some mathematical knowledge from earlier Egyptian and Babylonian mathematics.