This study notes covers Common Mistakes 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 8 of 9 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 8 of 9
Practice
12 questions
Recall
3 flashcards
Common Mistakes
✗ Wrong: Using (n) × 180° instead of (n − 2) × 180°
✓ Right: Always subtract 2 from the number of sides first
✗ Wrong: Interior angle = 360° ÷ n
✓ Right: That's the EXTERIOR angle! Interior = 180° − (360° ÷ n)
✗ Wrong: Sum of exterior angles = (n − 2) × 180°
✓ Right: Exterior angles ALWAYS sum to 360° (any polygon!)