Angles in a Polygon

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Angles in a Polygon

The interior (inside) angles of a polygon (a shape made of straight lines) are the angles inside the shape.

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Interior (inside) angles

  • The sum of the interior angles is (n - 2) × 180° where n is the number of sides the polygon has.
Illustrative background for Exterior anglesIllustrative background for Exterior angles ?? "content

Exterior angles

  • If you extend the side of a polygon outside the shape then the exterior angle is the angle between the extended line and the adjacent edge.
  • The exterior angles add up to 360°.
  • In a regular polygon the exterior angle + interior angle = 180°.

Jump to other topics


1.1Place Value

1.2Factors & Multiples


1.4Fractions, Decimals & Percentages

1.5Growth & Decay

1.6Measurements & Units



3Ratio, Proportion & Rates of Change

4Geometry & Measures



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