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Glite Dictionary
external angle

external angle

6.3
An angle outside a polygon that forms when one side is extended
  • noun
  • /ɪkˈstɜrnəl ˈæŋɡəl/
  • Specialized
translation icon : ángulo externo
  • The sum of all the external angles of a polygon is always 360 degrees.

Examples

  • To find the external angle of a regular pentagon, divide 360 by 5.

  • Each external angle in an equilateral triangle measures 120 degrees.

  • The external angle measures 120 degrees.

  • Can you find the external angle of this triangle?

  • Each external angle in an equilateral triangle is formed when one side is extended and measures 120 degrees.

  • The sum of all external angles in any polygon adds up to 360 degrees, regardless of the number of sides.

  • To calculate the external angle of a regular pentagon, you simply divide 360 degrees by the number of sides, which is 5.

Synonyms

exterior angle
vsexternal angle
  • Specialized
5.5

An angle outside a shape with straight sides made by a side and the next side extended

means the same but is an alternative name used for the same angle

How Internal

internal angle
  • Specialized
4.2
external angle
  • Specialized
6.3

Surface Forms

external angle singular
external angles plural

Morphology

external + angle

The meaning 'an angle formed outside a polygon' is directly and compositionally derived from 'external' (outside) + 'angle' (the measure between two lines). This adjective+noun combination follows standard semantic composition and is cross-linguistically transparent, so a B1 learner who knows both constituents would readily infer the meaning.

Etymology

The term external angle names the angle you see on the 'outside' of a shape when one side is extended. The word external points to 'outside' and angle means a corner or turn, so the phrase means the 'outside' turn at a corner and we use it to describe how much you turn when you go around a polygon.