Polygons
In this course, we will learn the names of polygons with 5 to 10 sides and how to identify them by their number of sides. We will also study the key polygon formulas, including the sum of interior angles and the formula for each interior angle of a regular polygon.
Related Lessons:
Names Of Polygons
Here are the standard names from 5 sides to 12 sides polygons:
- 5 sides – Pentagon
- 6 sides – Hexagon
- 7 sides – Heptagon
- 8 sides – Octagon
- 9 sides – Nonagon
- 10 sides – Decagon
- 12 sides – Dodecagon
Polygons Interior & Exterior Formula
For All Polygons with n sides
- Sum of interior ∠= \((n-2)\times180^0\)
- Sum of exterior ∠=\(360^o\)
- ext ∠ + int ∠ = 180° (∠ on str. line)
A regular polygon is a polygon with all its sides having the same length, and all its interior angles equal in measured. For a regular n-sided polygon:
To find the exterior angle
- exterior ∠ =\(\frac{360°}{n}\)
To calculate number of sides:
- \(n=\frac{360°}{ext ∠}\)