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Lesson Plan
Curated OER

Exploring Characteristics of Triangles

For Teachers 9th - 11th
Students draw triangles and explore the classification of each using the measures of interior angles and lengths of sides. They investigate the sum of the interior angles of various triangles and conjecture and prove the theorem: The...
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Interactive
Sophia Learning

Sophia: Sum of Angles in Polygons

For Students 6th - 8th
This tutorial with video and slideshow components investigate the characteristics of polygons as well as how to calculate the interior and exterior angles of any polygon. It offers two PowerPoint presentations and two videos that feature...
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Unit Plan
Cuemath

Cuemath: Convex Shapes

For Students 9th - 10th
A comprehensive guide for learning all about convex shapes with definitions, examples, and practice questions.
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Activity
Texas Instruments

Texas Instruments: What's the Angle?

For Teachers 9th - 10th Standards
Students discover properties of interior and exterior angles of convex polygons using the TI-89 and Geometer's Sketchpad.
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Activity
Texas Instruments

Texas Instruments: Investigating the Angle Sum Theorem of Polygons

For Teachers 9th - 10th
This activity will allow students to use Cabri Jr. to find the sum of the measures of interior angles of convex polygons and visually see how the Interior Angle Sum Theorem works.
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Activity
Other

Generalization

For Students 9th - 10th Standards
Learn how to construct convex polygons and the mathematical foundations of symmetry on this site.
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Interior Angles in Convex Polygons

For Students 9th - 10th
[Free Registration/Login may be required to access all resource tools.] Find the sum of the interior angles of a convex polygon.
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Activity
CK-12 Foundation

Ck 12: Interior Angles in Convex Polygons

For Students 9th - 10th
[Free Registration/Login Required] Students will move the pentagon points to explore convex polygons. Click learn more to watch a video and click challenge me to answer a practice question.
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Unit Plan
Sophia Learning

Sophia: Classifying Polygons

For Students 6th - 8th
This lesson explores the characteristics of various types of polygons. It includes two PowerPoint presentations that test students' understanding by grouping polygons in the correct categories.
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Handout
CK-12 Foundation

Ck 12: Geometry: Polygons Study Guide

For Students 9th - 10th
[Free Registration/Login may be required to access all resource tools.] This study guide focuses on polygons: convex vs concave, interior and exterior angles, and basic terminology for common polygons.
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Handout
Math Open Reference

Math Open Reference: Convex Polygon

For Students 9th - 10th
Learn about convex polygons with this handy reference guide. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
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Website
University of Regina (Canada)

University of Regina: Math Central: Interior Angle Measure of a Polygon

For Students 6th - 8th
This is a question response page from the University of Regina where one may find an algorithm for finding the number of degrees of any convex polygon.
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Handout
The Math League

The Math League: Figures and Polygons

For Students 3rd - 8th Standards
This website has basic definitions for most polygons, regular and irregular.
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Unit Plan
Other

George W. Hart: Polygons

For Students 9th - 10th Standards
This personal site presents some general information about polygons.
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Activity
Other

Intersecting Convex Polygons the Algorithm

For Students 9th - 10th
This site talks about how to check for the intersection of polygons. Computer programs calculating intersections are presented.