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Vocabulary For Polygons
Formulas and Examples for Polygons
Practice Problems for Polygons

Welcome! Here you will learn how to determine the relationships between measures of 

angles (interior and exterior) and the number of different polygons. 

Below are the angle amounts for figures that have three-sides to twelve-sides:

Name of Figure

Interior Angles Add Up To...

Exterior Angles Add Up To...

Triangle (three sides) 180 Degrees() 360
Quadrilateral (four sides)360360
Pentagon (five sides)540360
Hexagon (six sides)720360
Septagon (seven sides)900360
Octagon (eight sides)1080360
Nonagon (nine sides)1260360
Decagon (ten sides)1440360
Hendecagon (eleven sides)1620360
Dodecagon (twelve sides)1800360

Want to know how to find the sum of the angles of the interior angles of any polygon?
Formulas and Examples For Polygons