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

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

Coterminal Angle -- from Wolfram MathWorld

Heptagon - From Wolfram MathWorld, PDF

Solid Angle -- from Wolfram MathWorld

Solid Angle -- from Wolfram MathWorld

Wolfram, Alpha Meets MathWorld—Wolfram

Lesson Angle in a semicircle

Wolfram Mathworld in the Notebook Archive

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

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

Inscribed Angle -- from Wolfram MathWorld

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

Angle Standard Position -- from Wolfram MathWorld

Archimedean Solids - page includes images of each solid's net as

Contact Angle -- from Wolfram MathWorld