# Trigonometry Basics

#### Trigonometry Basics

The concept of Trigonometry is given by a Greek mathematician Hipparchus. Trigonometry is all about a right-angled triangle.

It is one of those divisions in mathematics that helps in finding the angles and missing sides of a triangle by the help of trigonometric ratios.

The angles are either measured in radians or degrees. The usual trigonometry angles are 0°, 30°, 45°, 60° and 90°, which are commonly used.

### Six Important Trigonometric Functions

The six important trigonometric functions (trigonometric ratios) are calculated by the below formulas using above figure. It is necessary to get knowledge regarding the sides of the right angle triangle, because it defines the set of important trigonometric functions.

 Functions Abbreviation Relationship to sides of a right triangle Sine Function sin Opposite side/ Hypotenuse Tangent Function tan Opposite side / Adjacent side Cosine Function cos Adjacent side / Hypotenuse Cosecant Function cosec Hypotenuse / Opposite side Secant Function sec Hypotenuse / Adjacent side Cotangent Function cot Adjacent side / Opposite side

## Trigonometry Ratios Table

The standard angles of trigonometrical ratios are 0°, 30°, 45°, 60° and 90°. The values of trigonometrical ratios of standard angles are very important to solve the trigonometrical problems.

The values of trigonometrical ratios of standard angles are very important to solve the trigonometrical problems. Therefore, it is necessary to remember the value of the trigonometrical ratios of these standard angles. The sine, cosine and tangent of the standard angles are given below in the table.