Trig functions are a set of mathematical functions used to describe the relationships between angles and sides of a triangle. The most commonly used trig functions are cosines, sines, tangents, and cosecants. Cosines are seven letter functions that represent the ratio of the adjacent side of a triangle to the hypotenuse. Sines are five letter functions that represent the ratio of the opposite side of a triangle to the hypotenuse. Tangents are eight letter functions that represent the ratio of the opposite side of a triangle to the adjacent side. Cosecants are nine letter functions that represent the reciprocal of the sine function.