Laxmi Rathour - Ward Number – ۱۶, Bhagatbandh, Anuppur ۴۸۴ ۲۲۴, Madhya Pradesh, India.
Dragan Obradovic - Elementary School "Jovan Cvijic", Kostolac-Pozarevac, Teacher of Мathematics, Serbia.
Shiv Tiwari - Department of Mathematics, L. E. College, Morbi-۳۶۳ ۶۴۲, Gujarat, India.
Lakshmi Mishra - Department of Mathematics, School of Advanced Sciences, Vellore Institute of Technology, Vellore ۶۳۲ ۰۱۴, Tamil Nadu, India.
Vishnu Mishra - Department of Mathematics, Indira Gandhi National Tribal University, Lalpur, Amarkantak ۴۸۴ ۸۸۷, Madhya Pradesh, India.

Trigonometry is a part of mathematics which deals with specific functions of angles and their application, and it is studies of the dependence between the sides and angles of a triangle. The word trigonometry is associated the operations between the sides and angles of the triangles. Initially, it aimed to calculate the values of all elements of a triangle (height, centroid length, bisector, radius, area and angles) using data sufficient to determine the triangle. In the paper, trigonometric functions are defined, and some statements about trigonometric identities are stated and proved.

Mathematics, Trigonometric functions, Trigonometric identities