Angle -- from Wolfram MathWorld

Given two intersecting lines or line segments, the amount of rotation about the point of intersection (the vertex) required to bring one into correspondence with the other is called the angle theta between them. The term "plane angle" is sometimes used to distinguish angles in a plane from solid angles measured in space (International Standards Organization 1982, p. 5). The term "angle" can also be applied to the rotational offset between intersecting planes about their

Right Angle -- from Wolfram MathWorld

Distance between Two Vecten Points - Wolfram Demonstrations Project

2: Graphical representation of Euler angles. Source

Angles: Definition, Parts, Types, Degrees, Properties, Examples

Contact Angle -- from Wolfram MathWorld

Euler Angles -- from Wolfram MathWorld

Central Angle -- from Wolfram MathWorld

Angle Standard Position -- from Wolfram MathWorld

Curlicue Fractals - JMP User Community

Brocard Angle -- from Wolfram MathWorld

Distance between Two Fermat Points - Wolfram Demonstrations Project

CUDA for quaternions (hyper-complex numbers) operations - CUDA

Wolfram Math World: Law of Cosines Handout for 9th - 10th Grade