Geometry & MeasuresKey Facts

Common Polygon Angles

Part of Angles in PolygonsGCSE Mathematics

This key facts covers Common Polygon Angles within Angles in Polygons for GCSE Mathematics. Revise Angles in Polygons in Geometry & Measures for GCSE Mathematics with 12 exam-style questions and 3 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 3 of 9 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 3 of 9

Practice

12 questions

Recall

3 flashcards

Common Polygon Angles

Polygon Sides (n) Interior Sum Each Interior (regular) Each Exterior (regular)
Triangle 3 180° 60° 120°
Quadrilateral 4 360° 90° 90°
Pentagon 5 540° 108° 72°
Hexagon 6 720° 120° 60°
Octagon 8 1080° 135° 45°
Decagon 10 1440° 144° 36°

Keep building this topic

Read this section alongside the surrounding pages in Angles in Polygons. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Angles in Polygons

What is the sum of the interior angles of a hexagon?

  • A. 540°
  • B. 720°
  • C. 900°
  • D. 360°
1 markfoundation

Explain how the formula (n − 2) × 180° for the sum of interior angles of a polygon is derived.

2 markshigher

Quick Recall Flashcards

Interior Angle Sum
Sum = (n - 2) × 180° for n-sided polygon
Exterior Angle Sum
Always 360° for any polygon

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