exterior angle
Học thuậtThân thiện
Definition
- Noun:
- The supplement of an interior angle of a polygon: An exterior angle is the angle formed between one side of a polygon and the extension of an adjacent side. It is supplementary to the interior angle at that vertex, meaning the two angles add up to 180 degrees.
Usage Examples
- Noun:
- To find the measure of an exterior angle of a regular hexagon, you can divide 360 by the number of sides.
- In the diagram, the exterior angle is clearly marked outside the triangle.
Advanced Usage
- Sum of Exterior Angles: A key property is that the sum of the exterior angles of any convex polygon, one at each vertex, is always 360 degrees, regardless of the number of sides.
- The theorem that the sum of the exterior angles is 360 degrees is fundamental in geometry.
Variants and Related Words
- External Angle: A less common but synonymous term for exterior angle.
- Interior Angle: The angle inside the polygon at a vertex, which is supplementary to the exterior angle.
Synonyms
- External angle
Related Concepts (Not Phrasal Verbs/Idioms)
- Supplementary Angles: Two angles whose measures sum to 180 degrees. An exterior angle and its corresponding interior angle are supplementary.
- Polygon: A closed plane figure bounded by straight lines, which has interior and exterior angles.
Noun
- the supplement of an interior angle of a polygon