What Is Trigonometry

Trigonometry is the branch of mathematics that deals with the study of relationships between the sides and angles of triangles. Trigonometry is an essential study of geometry as every shape can be broken into different collections of triangles. Moreover, trigonometry has astoundingly interrelationships with other mathematics branches especially in logarithms, infinite series, and calculus.

History of Trigonometry

Trigonometry just like algebra follows the same path. Trigonometry was first developed in the early Middle East. Through immigration and trade, trigonometry moved to India, Greece, medieval Arabia and lastly Europe where the colonialism developed the version that most students learn today.

Trigonometric Functions

The study of trigonometry involves primarily three functions. They include:

• Sine function
• Cosine function
• Tangent function

The sine function is normally written as sin(x),cosine function written as cos(x) and the tangent function written as tan(x).Before we explain deep on the functions mentioned above, it is important to learn some of the commonly used terminologies. These terminologies are:

• Adjacent angles and sides

  Angles and sides that touch are called adjacent angles and sides respectively. Every side of a right angle has two adjacent angles.

• Opposite Angles and Sides

  Angles and sides that do not touch each other are described as an opposite.

• Hypotenuse Angles and Sides

In the right triangle, the side which is opposite to the right angles is described as the hypotenuse.

Sine, Cosine, and Tangent

The sine, cosine, and tangent of angle A are calculated as:

Sin (A) = Opposite/hypotenuse

Cos (A) = Adjacent/hypotenuse

Tan (A) = Opposite/adjacent

In the above formula, the sign (/) means division.

Shapes Other Than Right Triangles

Trigonometry is not limited only to right triangles. It applies to any triangle or shape that has straight ends. To determine the angles and lengths of such shapes, two laws are strictly followed. These laws are: