# Angle, Direction functions

These functions works on two similar idea.

- An angle is the length of the arc of the unit circle between the two ray.
- A direction is a unit-length vector, given by either the (x, y) coordinates or an angle starting from the (1, 0) vector counter-clockwise.

Geometry::NormFi02Pi

Geometry::ArcSin

Geometry::ArcCos

Geometry::ArcTan

Geometry::AddAngle

Geometry::SubAngle

Geometry::MidAngle

Geometry::IsInsideAngle

Geometry::IsLessThanAngle

Geometry::NegativeArc

Geometry::TMDirCoeffs

Geometry::TMDir2Angles