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Article: angle
- Article from:
- The Columbia Encyclopedia, Sixth Edition
CopyrightThe Columbia Encyclopedia, Sixth Edition. Copyright 2008 Columbia University Press. (Hide copyright information)
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angle in mathematics, figure formed by the intersection of two straight lines; the lines are called the sides of the angle and their point of intersection the vertex of the angle. Angles are commonly measured in degrees (°) or in radians. If one side and the vertex of an angle are fixed and the other side is rotated about the vertex, it sweeps out a complete circle of 360° or 2π radians with each complete rotation. Half a rotation from 0° or 0 radians results in a straight angle, equal to 180° or π radians; the sides of a straight angle form a straight ...