Curated OER
Sum of Interior Angles
In this sum of interior angles worksheet, 10th graders solve 10 different problems that are related to determining the sum of various interior angles in figures. First, they determine the sum of the interior angles of a dodecagon. Then,...
Curated OER
Properties of Angles
In this properties of angles worksheet, 10th graders solve and complete 3 different types of problems. First, they calculate the value of the missing angles in each diagram and explain the reasons for their answer. Then, students...
Curated OER
Polygon Mobiles
Students explore a variety of shapes and angles and create mobiles with information about a selected polygon. Both common and "not-so common" polygons are examined.
The Math League
The Math League: Figures and Polygons
This site provides definitions of different types of polygons and figures.
The Math League
The Math League: Figures and Polygons
This website has basic definitions for most polygons, regular and irregular.
The Math League
The Math League: Figures and Polygons: Nonagons
This site provides definitions and examples of the various types of polygons including nonagons.
University of Georgia
University of Georgia: Inter Math: Nonagon
This site gives the general definition of a nonagon with examples of a regular (convex) and irregular concave nonagons. There are links to related terms, challenging problems, more information, and the interactive check point involving...
Calculator Soup
Calculator Soup: Regular Polygon Calculator
Use this calculator to calculate properties of a regular polygon. Enter any 1 variable plus the number of sides or the polygon name. Calculates side length, inradius, circumradius, area, and perimeter.
Math Open Reference
Math Open Reference: Nonagon (9 Gon)
Learn about nonagons with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.