T

Nicolò Fontana Tartaglia (ca. 1499-1557)

Born in Italy.
His work in algebra led to the first generalized solution of cubic equations.
He made contributions to fundamental arithmetic, ballistics, military engineering, and survey instruments.
Thales (ca. 625 BCE - ca. 547 BCE)

Born in Turkey.
Tradition states that he was the first to prove these geometric results:

(1) vertical angles are equal;
(2) the angle sum of a triangle equals two right angles;
(3) the base angles of an isosceles triangle are equal;
(4) an angle inscribed in a semi-circle is a right angle.
Theaetetus (417 BCE - 369 BCE)

Born in Greece.
He developed the theory of incommensurable magnitudes.