Identifying Regular and Irregular Polygons

Sheena Doria

This educational video provides a clear and comprehensive introduction to the properties of regular and irregular polygons. The narrator uses a friendly, animated classroom format to define the specific criteria that make a polygon "regular"—specifically, that it must be both equilateral (having equal sides) and equiangular (having equal angles). Through side-by-side comparisons of familiar shapes like squares, rectangles, triangles, and rhombuses, viewers are taught to identify these properties using visual cues like tick marks and angle measures. The content systematically addresses common misconceptions, such as the belief that having equal sides is enough to be regular (disproven using the rhombus) or that having equal angles is sufficient (disproven using the rectangle). The video moves from basic definitions to analyzing specific polygons like pentagons, hexagons, and octagons, helping students differentiate between "regular" versions and their irregular counterparts. Ideal for upper elementary geometry units, this resource serves as excellent direct instruction or review material. It concludes with a guided quiz section where students must identify polygons based on verbal descriptions, reinforcing vocabulary terms like "congruent," "dodecagon," and "decagon." The clear visual aids, including congruent markers and angle arcs, model exactly how students should annotate shapes in their own mathematical work.