Multiple choice general knowledge math & puzzles heptadecagon 15 16 17 18 Reveal answer Fill a bubble to check yourself C Correct answer Explanation A heptadecagon is a polygon with 17 sides and 17 angles. The name is derived from 'hepta' (7) and 'deca' (10). 15 is a pentadecagon, and 16 is a hexadecagon.