Because it has such a strong ability to explain space and the relationships between angles, trigonometry is used in almost every branch of modern physics, according to Clark University. Any field of physics that includes the use of angles or sides uses trigonometry. Some of the first fields in physics, statics and optics relied heavily on trigonometry during their pioneering stages.
Trigonometry is the mathematical science that studies the relationships between lengths and angles of triangles. However, it has applications that extend to such shapes as circles, spheres and other three-dimensional geometric constructs. Because of this, trigonometry is incredibly useful in understanding and modeling the real world. Certain constructs, such as suspended crates and pulley systems, can be described with series of angles and lines. Some applications of trigonometry include those with angular momentum and movement up or down inclines.
Trigonometry is also vital to the understanding of light rays and how they behave. Because complex problems, such as the bending of a light as it passes through glass, can be broken down into mathematical components, they can be solved and analyzed with trigonometric methods. Angles of incidence and refraction inside of triangular prisms can be solved for with trigonometry. Physicists can use information like this to estimate the refractive indexes of certain materials.