Trigonometry
lastmod 2023-02-02created 2014-09-037 edits
Trigonometry is a branch of mathematics that studies various geometric figures based on the relationships between the sides and angles of triangles. The English word trigonometry comes from the Greek trigonon (triangle) and metro (measure).
Trigonometric functions
Trigonometric functions are functions of an angle used in mathematics. They are mainly used for assumptions about triangles or periodic phenomena.
See here for details.
- Law of sines: Given two angles and the length of one side, the lengths of the other two sides can be found.
- Law of cosine: Given the lengths of two sides and the included angle, the length of the remaining side can be found. Given the lengths of three sides, the angles of the triangle can be found.
- Trigonometric functions details
Terminology
- Pi (PI)
- Pi is a mathematical constant representing the ratio of a circle's circumference to its diameter.
-
π ≒ 3.1415926535 ...
- Radian
- One radian is the size of the central angle subtended by an arc on the circumference whose length equals the radius; it is a dimensionless unit.
- Also called circular measure, and abbreviated rad.
- Sexagesimal system (Degrees)
- The degree is a unit of angle; one full rotation divided into 360 equal parts is 1 degree.