A triangle is a three sided geometric shape. The shape forms a basis for the subject of trigonometry and is used throughout mathematics and programming.
An angle is defined as the amount of rotation between two rays. Angles are measured using degrees and radians. A full rotation in degrees is 360°. A full rotation in radians is approximately 6.283 radians or τ (tau) radians.
The law of sines is an equation that relates the three sides of a triangle with the three angles of a triangle using the sine function.
The law of cosines is a more general form of pythagoreans theorem that relates the squares of the sides together using the cosine function.
A right triangle is a triangle where one of the three angles is a perpendicular angle. There are three sides of the right triangle: the adjacent, opposite, and hypotenuse sides.
The area of a triangle is given by one half multiplied by its width and height.
The area between two vectors is given by the magnitude of their cross product. This formula is a generic way to find the area of any triangle given three points.