**Trigonometry is used by engineers, medical services technicians, mathematicians, data entry specialists, loggers, statisticians, actuaries, drafters, chemists, economists, physicists, registered nurses, building inspectors, boilermakers, machinists and millwrights.** Approximately 50 different jobs in categories including management, farming, professional services, administration, construction, production and installation use trigonometry.

Trigonometry is a type of mathematics that studies angles and their relationships to each other. The field was first studied in the third century B.C. as a way of applying geometry to astronomy. Early astronomers noted fixed relationships between the sides and angles of right triangles. They also discovered that if they knew the value of one angle in such a triangle, they could determine the other lengths and angles using an algorithm. The calculations came to be known as trigonometric functions. Today, the functions are used in many fields, including electrical and mechanical engineering, acoustics, ecology, biology, astronomy, physics and surveying.

Trigonometric principles can also be applied to triangles that do not include right angles. However, most calculations are made on right triangles because any triangle can be converted to a right triangle through bisection. An exception is spherical trigonometry, which is the study of triangles on spheres in elliptic geometry. The field is a fundamental component of navigation and astronomy.