Textbook in PDF format
There are different styles of interpretation of a circle. There would be something undiscovered special characteristics of circle to us. This inspired to search the trigonometric ratios. During development of the new method for trigonometric relations, I faced un-numbered problems of algebra, geometry and arithmetic. There are five different methods - one is ratio-based and four are chord-based. Four methods give exact trigonometric values. It opens new interpretation for classical method of trigonometry