Exploring Polygon Classification

Objective:

Students will be able to classify polygons based on the number of sides and angles, distinguishing between convex and concave polygons.

Assessment:

Students will be given a worksheet with various polygons, and they will have to correctly identify and classify each polygon based on the number of sides and angles.

Key Points:

• Understand the definition of a polygon as a closed, 2-dimensional figure made of line segments

• Differentiate between convex and concave polygons

• Identify and name polygons based on the number of sides and angles

• Common Polygon Definitions:

  1. Triangle: 3 sides

  2. Quadrilateral: 4 sides

  3. Pentagon: 5 sides

  4. Hexagon: 6 sides

  5. Heptagon: 7 sides

  6. Octagon: 8 sides

  7. Nonagon: 9 sides

  8. Decagon: 10 sides

  9. Dodecagon: 12 sides

  10. N-gon: n sides (general term for any polygon with n sides)

Opening:

• Show images of different polygons and ask students to identify and discuss their characteristics

• Pose the question: "What defines a polygon, and how can we classify them based on their features?"

Introduction to New Material:

• Discuss the definition of a polygon and its key characteristics

• Explain the difference between convex and concave polygons

• Common Misconception: All polygons have to be regular in shape

Guided Practice:

• Provide examples of polygons for students to classify as convex or concave

• Scaffold questioning from easy (triangles, squares) to hard (pentagons, hexagons)

• Monitor student performance by circulating the classroom and providing guidance as needed

Independent Practice:

• Students will work on a worksheet where they identify and classify polygons

• They will demonstrate their understanding by correctly naming each polygon and identifying its properties

Closing:

• Ask students to share one thing they learned about polygon classification today

• Summarize the key differences between convex and concave polygons

Extension Activity:

• For early finishers, provide a set of irregular polygons and challenge them to classify and name each one

Homework:

• Homework Activity: Create a poster showcasing different polygons found in everyday objects, labelling them with their names and properties

Standards Addressed:

• CCSS Standard: G-CO.A.3a - Given a rectangle, parallelogram, trapezoid, or regular polygon, describe the rotations and reflections that carry it onto itself.

• CCSS Standard: G-CO.A.3b - Identify types of line symmetry for given polygons.