Naming Polygons and Finding Interior Angles

The Organic Chemistry Tutor

This concise mathematics tutorial introduces students to the naming conventions of polygons based on their side counts and demonstrates how to calculate the sum and individual measures of interior angles in regular polygons. The video utilizes a digital whiteboard format to visually construct shapes ranging from triangles to octagons, explicitly defining what makes a polygon "regular" (congruent sides and angles). It provides a clear, step-by-step application of the interior angle sum formula, (n-2) × 180, solving for both a pentagon and a hexagon. The key themes explored include geometric vocabulary (congruent, regular, interior angles), classification of shapes, and algebraic substitution. The video focuses heavily on procedural fluency, showing students exactly how to substitute the number of sides (n) into the formula to find the total sum of angles, and then dividing by n to find the measure of a single angle in a regular polygon. For educators, this video serves as an excellent direct instruction tool or review resource for a Geometry or Pre-Algebra unit. It effectively bridges the gap between identifying shapes and performing calculations with them. Teachers can use this video to model problem-solving steps before having students practice with other polygons (like heptagons or decagons) or to reinforce the connection between the number of sides and the total degrees within a shape.