kathets
Kathets is a rarely used plural form of kathetus, a term in Euclidean geometry referring to the two sides of a right triangle that meet at the right angle. In standard English geometry, these sides are more commonly called the catheti, with the singular cathetus. The word kathetus comes from the Greek kathetos meaning perpendicular; over time, math texts have preferred cathetus and catheti, though kathets may appear in some historical or translated works.
Definition and notation: In a right triangle, the two legs are the kathets or catheti. If the
Relations to angles: For the angle A opposite leg a, sin A = a/c, cos A = b/c, and
Applications: Kathets/catheti are fundamental in geometry and trigonometry. They are used to compute unknown side lengths,
See also: Right triangle, Hypotenuse, Cathetus, Catheti, Pythagorean theorem.