In this lesson, students explore the classification of polygons, learning key concepts such as the definitions of regular and irregular polygons, and specific examples including pentagons, hexagons, and octagons. The teacher emphasizes that polygons are multi-sided, closed, two-dimensional shapes with sides, vertices, and angles, using engaging visuals and interactive games to reinforce the material. By the end, students participate in a fun activity to identify whether various shapes are polygons or not.