Bibliographic Information:
Muschla, Judith A. and Gary R. Muschla. “Polygons and Lines of Symmetry.” Geometry Teachers’s Activities Kit: Ready-to-use Lessons & Worksheets for Grades 6-12. West Nyack, New York. © 2000, pages 130. (ISBN 0-13-016777-0)
Mathematical Concept: Symmetry
Grade Levels: 6th – 7th
NC Standard Course of Study:
Competency 3: The learner will understand and use properties and relationships of geometric figures in geometry.
3.01: Using three-dimensional figures:
- Identify, describe, and draw from various views (top, side, front, corner).
- Build from various views.
- Describe cross-sectional views.
3.02: Identify, define, and describe similar and congruent polygons with respect to angle measures, length of sides, and proportionality of sides.
3.03: Use scaling and proportional reasoning to solve problems related to similar and congruent polygons.
Materials:
Pencils
Rulers
Protractors
Unlined Paper (optional)
Handout
Detailed Description:
Students will draw polygons that have a specific number of lines of symmetry. Students should work individually to complete this activity. Because the sides and angles of many kinds of polygons are congruent, they can be used to illustrate symmetry. In this activity, as students draw polygons, they will also consider their lines of symmetry.
Procedure:
1. Introduce this activity by explaining that symmetry is a relationship in which opposite sides of an object or figure are mirror images of each other.
2. Ask students if they can name examples of symmetry in the world/nature? (Human beings have 2 eyes, 2 ears, 2 arms, 2 legs; most animals are symmetrical; many flowers; buildings; butterflies)
3. Handout copies of the worksheet titled “Polygons and Lines of Symmetry.”
4. Review the instructions with the students.
5. Students are to complete the activity independently.
6. Once all students are finished with the assignment, the class will go over the answers.
Extension Assignment:
As an extension to this assignment, the class may be assigned to form a poster of symmetrical images found in magazines. Students should cut out the figure, glue it onto poster board, and draw its line of symmetry.
Attachment: Worksheet/Activity Student Page
Symmetry – Polygons and Lines of Symmetry – Handout
