Illuminations: Polygon Capture
Illuminations (National Council of Teachers of Mathematics)

In this lesson, students classify polygons according to more than one property at a time.

Illuminations: Sorting Polygons
Illuminations (National Council of Teachers of Mathematics)

Students identify and classify polygons according to various attributes.

Illuminations: Reflect On This
Illuminations (National Council of Teachers of Mathematics)

This lesson, adapted from an activity in Navigating through Geometry in Grades 9‑12, requires students to investigate reflections using hinged mirrors.

NRICH: Pick's Theorem
NRICH (University of Cambridge)

Polygons drawn on square dotty paper have dots on their perimeter (p) and often internal (i) ones as well. Find a relationship between p, i and the area of the polygons.

GeoGebra: Polygons - IM 6.1.11
GeoGebra

“Polygons” from IM Grade 6 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Congruent Polygons IM 8.1.12
GeoGebra

“Congruent Polygons” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Polyon Interior Angles - Investigations
GeoGebra

Polygon Interior Angles: Discovery Learning Explorations for GeoGebra Classroom

GeoGebra: Similar Polygons IM 8.2.7
GeoGebra

“Similar Polygons” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Building Polygons (Part 2) IM 7.7.7
GeoGebra

“Building Polygons (Part 2)” from IM Grade 7 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Building Polygons (Part 1) IM 7.7.6
GeoGebra

“Building Polygons (Part 1)” from IM Grade 7 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Triangles with 3 Common Measures IM 7.7.8
GeoGebra

“Triangles with 3 Common Measures” from IM Grade 7 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Regular Tessellations IM 8.9.2
GeoGebra

“Regular Tessellations” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.