That's the definition of trigonometry. Triangles are completely dependent upon their side lengths, and can be defined by only three values.
He defined the spherical triangle
It is the study of triangles and their properties. The word 'trigonometry' means three measurements.
Most branches of mathematics - including trigonometry - deal with numbers. The square root of three is a number.
There are many formulae in trigonometry, not just three. So the question cannot be answered without knowing which three you mean.
An identity is like an equation which is true for all values of the variable.
Converting three dimensional settings for projecting onto 2-d screens requires trigonometry.
The word, trigonometry" is derived from trigon = triangle + metry = measurement. It is based on the study of angles of a triangle and their properties. Although trigonometric ratios are often introduced to students in the context of triangles, their properties for all angles.For example, trigonometric functions are well defined for angles with negative values as well as for more than 180 degrees even though no triangle can possibly have angles with such measures.
angle can be defined as sin-1=O/H, cos-1=/H, or Tan-1=O/A
A way to remember the definitions of the three most common trigonometry functions: sin, cos and tan. Used as a memory aid for the definitions of the three common trigonometry functions sine, cosine and tangent.
In geometry, similar shapes have the same angles. This means that the values of the basic trigonometric functions of these angles are the same.
Algebra, Trigonometry and Calculus