What was Euclid's contribution to mathematics that's still in use today ? (point) his textbook The Elements his design of the sun-centered solar system his system of logic his measurement of the size of the Earth

Euclid's major contribution to mathematics that is still in use today is his textbook **"The Elements."** This work systematically compiled and organized the knowledge of geometry of his time and laid the groundwork for logic and proof in mathematics, which are foundational to the field.