Regular Polygons

📋 Course Outline

1. Polygon Types and Terminology
2. Convexity and Concavity
3. Interior Angle Sums
4. Exterior Angle Sums
5. Angles of Regular Polygons
6. Symmetry of Regular Polygons
7. Circles and Central Angles
8. Perimeter and Area Formulas

📖 1. Polygon Types and Terminology

🔑 Key Concepts & Definitions

• Polygon : A simple closed plane figure formed by three or more line segments joined end to end, with no two successive segments collinear.

★ Must-know

• The sides of a polygon are its forming line segments, vertices are the common endpoints of two sides, and interior angles are the angles formed inside the polygon.

Further detail

• A polygon with n sides is commonly named an n-gon; the course lists triangle, quadrilateral, pentagon, hexagon, heptagon, octagon, nonagon, and decagon for 3 through 10 sides.

📖 2. Convexity and Concavity

🔑 Key Concepts & Definitions

• Convex Polygon : Has every interior angle less than 180°, and its vertices point outward.
• Concave Polygon : Has at least one interior angle greater than 180°, with vertices that can point inward and outward.

📝 Essential Points