Trigonometry is a field of mathematics specializing in specific angle functions and their utilization for calculations. In trigonometry, six operations of an angle are commonly used. Sine (sin), cosine (cos), tangent (tan), cotangent (cot), secant (sec), and cosecant are their names and abbreviations (CSC). The figure depicts these six trigonometric functions similar to a right triangle. The sine of A, or sin A, of a triangle, for example, is the ratio of the side opposite to A to the side opposite to the right angle (the hypotenuse); the other trigonometry functions are described similarly. These features are attributes of angle A independent of the size of the triangle, and values obtained were computed for many directions before computers made trigonometry tables obsolete. Trigonometric functions are utilized for achieving unknown angles and distances from established or evaluated angles in geometric figures. Trigonometry arose from the necessity to calculate angles and distances in fields such as astronomy, cartography, surveying, and artillery range discovery. Plane trigonometry addresses issues involving angles and distances in a single plane. Spherical trigonometry considers applications to similar issues in even more than one plane of three-dimensional space.
