The three fundamental trigonometric ratios, namely sine, cosine, and tangent, each give the ratio of the lengths of the two sides of a right-angled triangle. A right-angled triangle's missing sides or angles can be found using the trigonometry formulas sin, cos, and tan. Hipparchus used the principles of trigonometry to establish the relationship between the sides and angles of a right triangle, whereas Pythagoras focused on the relationship between a right triangle's sides through the Pythagorean theorem. He fundamental trigonometric ratios of sin, cos, and tan are used to study the relationship between the angles and sides of a triangle, particularly a right-angled triangle.
