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Mathematics vocabulary · Geometry

Angle

Meaning in mathematics, with examples

/ˈæŋɡəl/nounCore term

In mathematics, angle means: The amount of turn between two lines or rays that meet at a point, measured in degrees or radians.

In Turkish: açı

How it is used

You measure, calculate, bisect and label angles. The main types are acute (less than 90°), right (exactly 90°), obtuse (between 90° and 180°) and reflex (more than 180°). Angles are often named with three letters, as in 'angle ABC'.

Example sentences

  1. Measure the angle with a protractor and round to the nearest degree.

  2. Angle ABC is obtuse, so this can't be a right triangle.

Common collocations

  • measure an angle
  • acute angle
  • obtuse angle
  • interior angle
  • angle of elevation
  • right angleAn angle of exactly 90 degrees, like the corner of a square, usually marked on diagrams with a small square.
  • triangleA flat shape with three straight sides and three angles; the angles inside any triangle always add up to 180 degrees.
  • radianA unit for measuring angles: the angle at the centre of a circle made by an arc as long as the radius. A full turn is 2π radians, or 360°.
  • vertexA corner point where two or more lines or edges meet, such as a corner of a triangle or a cube; also the turning point of a parabola.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Geometry

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