Polygon Party: Classifying Shapes!
Lesson Description
Video Resource
Key Concepts
- Definition of a polygon: closed figure with 3 or more line segments
- Classification of polygons by number of sides (triangle, quadrilateral, pentagon, hexagon, heptagon, octagon, nonagon, decagon)
- Regular vs. Irregular polygons
- Diagonals in polygons and their relation to triangles
- Formula for the sum of interior angles: (number of sides - 2) * 180 degrees
Learning Objectives
- Students will be able to define a polygon and identify shapes that are and are not polygons.
- Students will be able to classify polygons based on the number of sides they have (up to 10 sides).
- Students will be able to differentiate between regular and irregular polygons.
- Students will be able to calculate the sum of the interior angles of a polygon using the formula (n-2) * 180 degrees.
Educator Instructions
- Introduction (5 mins)
Begin by asking students what they already know about shapes. Review triangles and quadrilaterals briefly. Introduce the video 'How to Classify Polygons' and explain that they will be learning about different types of shapes and how to tell them apart. - Video Viewing (7 mins)
Play the video 'How to Classify Polygons'. Encourage students to pay close attention to the definitions and examples provided. - Discussion (8 mins)
After watching the video, facilitate a class discussion about the key concepts. Ask students to define a polygon in their own words and provide examples. Discuss the difference between regular and irregular polygons. Go over each polygon type (triangle - decagon) and how many sides each has. - Interactive Activity: Polygon Sort (10 mins)
Divide students into small groups and provide each group with a set of pre-cut shapes (various polygons and non-polygons). Have them sort the shapes into two categories: Polygons and Not Polygons. Then, within the 'Polygons' category, have them further sort the shapes by the number of sides and label each group (triangle, quadrilateral, etc.). - Calculating Interior Angles (10 mins)
Introduce the concept of diagonals and how they divide a polygon into triangles. Explain the formula (n-2)*180 for calculating the sum of interior angles. Work through a few examples together, such as a hexagon and an octagon. Have students practice calculating the interior angles of different polygons using the formula. The table in the video can be used as a visual aid and to show the pattern. - Wrap-up and Assessment (5 mins)
Review the key concepts one last time. Administer a short multiple-choice quiz to assess student understanding.
Interactive Exercises
- Polygon Scavenger Hunt
Have students find examples of different polygons in the classroom or at home. They can take pictures or draw the shapes and label them. They should also identify whether the shape is regular or irregular. - Polygon Art
Encourage students to create artwork using only polygons. They can draw different shapes, color them in, and create a mosaic or picture. This allows them to practice identifying and classifying polygons in a creative way.
Discussion Questions
- What is the difference between a polygon and a shape that is NOT a polygon?
- Can you name some real-world examples of different types of polygons?
- What does 'equilateral' mean? What does 'equiangular' mean?
- How does drawing diagonals help us understand the angles inside a polygon?
Skills Developed
- Shape recognition and classification
- Application of geometric vocabulary
- Problem-solving using formulas
- Pattern recognition
- Critical thinking
Multiple Choice Questions
Question 1:
Which of these is NOT a polygon?
Correct Answer: Circle
Question 2:
A shape with four sides is called a:
Correct Answer: Quadrilateral
Question 3:
Which of these shapes has 5 sides?
Correct Answer: Pentagon
Question 4:
A regular polygon has sides that are:
Correct Answer: All the same length
Question 5:
Which of these shapes has 8 sides?
Correct Answer: Octagon
Question 6:
A shape with three sides is called a:
Correct Answer: Triangle
Question 7:
What is the name of a polygon with 6 sides?
Correct Answer: Hexagon
Question 8:
What does 'equilateral' mean?
Correct Answer: All sides the same
Question 9:
A polygon with ten sides is called a
Correct Answer: Decagon
Question 10:
Which of the following is a closed shape made of line segments?
Correct Answer: Polygon
Fill in the Blank Questions
Question 1:
A _________ is a closed shape with three or more straight sides.
Correct Answer: polygon
Question 2:
A shape with four sides is called a __________.
Correct Answer: quadrilateral
Question 3:
A polygon with five sides is called a __________.
Correct Answer: pentagon
Question 4:
A polygon where all sides are the same length and all angles are the same is called _________.
Correct Answer: regular
Question 5:
A shape with eight sides is called an __________.
Correct Answer: octagon
Question 6:
The lines that connect one corner to a non-neighboring corner of a polygon are called __________.
Correct Answer: diagonals
Question 7:
A polygon with six sides is called a __________.
Correct Answer: hexagon
Question 8:
A polygon with seven sides is called a __________.
Correct Answer: heptagon
Question 9:
A polygon with nine sides is called a __________.
Correct Answer: nonagon
Question 10:
To find the number of triangles in a polygon you can use the formula X - 2, where X is the number of _________.
Correct Answer: sides
Educational Standards
Teaching Materials
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