NOTICE: Citizendium is still being set up on its newer server, treat as a beta for now; please see here for more. Citizendium - a community developing a quality comprehensive compendium of knowledge, online and free. Click here to join and contribute—free CZ thanks our previous donors. Donate here. Treasurer's Financial Report -- Thanks to our content contributors. --

Rectilinear angle (geometry)

(Redirected from Angle)

Main Article
Talk
Related Articles  [?]
Bibliography  [?]
Citable Version  [?]

This editable Main Article is under development and not meant to be cited; by editing it you can help to improve it towards a future approved, citable version. These unapproved articles are subject to a disclaimer.
Diagram showing the terminology of an angle including arms (in red), vertex (in light blue) and angle (in green)

A rectilinear angle or angle is the "steepness" between two straight lines. The point at which the lines intersect is called the vertex. The parts of the line that extend from the vertex and surround the "steepness" are called the arms.

This angle is measured in degrees (parts of 360). This angle can also be measured in radians.

There are various special types of angles:

Obtuse angle

Diagram showing an obtuse angle (in green)

An obtuse angle is one where the magnitude of the angle is greater than a right angle, but less than a straight angle.

Acute angle

Diagram showing an acute angle (in green)

An acute angle is one where the magnitude of the angle is less than a right angle.

Straight angle

Diagram showing a straight angle (in green)

A straight angle is the angle formed on a straight line. It is equal on both sides of the line. It is equal to the sum of two right angles.