Uploaded May 2025 | Updated September 2026, 2 weeks ago
How do you find the interior angles of a regular nonagon (9-sided polygon)? While there is a bonus formula you can use here, we prefer not to rely on formulas if we can derive the answer via other methods.
Brilliant Prep offers group and 1:1 instruction for all sections of the SAT & ACT. Check out brilliantprep.com or email info (AT) brilliantprep (DOT) com
How do you find the interior angles of a regular nonagon (9-sided polygon)? While there is a bonus formula you can use here, we prefer not to rely on formulas if we can derive the answer via other methods.
Brilliant Prep offers group and 1:1 instruction for all sections of the SAT & ACT. Check out brilliantprep.com or email info (AT) brilliantprep (DOT) com
![Do hard questions first? ⏰ Tips for High Scorers #2 [SAT/ACT]](https://i.ytimg.com/vi/eeGhOxSmV88/mqdefault.jpg "Do hard questions first? ⏰ Tips for High Scorers #2 [SAT/ACT]
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