Regular Polygons

Introduction

A Polygon is a many-sided shape.

A Regular Polygon is a many-sided shape with all sides and angles the same.

An important idea in Regular Polygons is that of symmetry ........ an example of symmetry ?

Eight Regular PolygonsWe will be looking at eight regular polygons:1. Equilateral Triangle2. Square3. Regular Pentagon4. Regular Hexagon5. Regular Heptagon6. Regular Octagon7. Regular Nonegon8. Regular Decagon

Equilateral Triangle

3 Sides3 Lines of SymmetryRotational Symmetry of Order 3

Square

4 Sides4 Line of SymmetryRotational Symmetry ofOrder 4

Regular Pentagon

5 Sides5 Lines of SymmetryRotational Symmetry ofOrder 5

Regular Hexagon

6 Sides6 Lines of SymmetryRotational Symmetry of Order 6

Regular Heptagon

7 Sides7 Lines of SymmetryRotational Symmetry of Order 7

Regular Octagon

8 Sides8 Lines of SymmetryRotational Symmetry ofOrder 8

Patterns of SymmetryPatterns can be created inside and outside .....

Interior and Exterior Angles

You will need to know these definitions ...

Exterior Angles

Interior Angles

Interior and Exterior Angles

360

Number of Sides=Exterior Angles

180 – Exterior Angle =Interior Angles

Ancient Tiling Because of symmetry Regular Polygons have

been used for tiling for thousands of years ...

SUMMARY

• Regular Polygons have equal sides and angles

• They have Line and Rotational Symmetry

• Each has unique Interior and Exterior Angles

• They can produce pattern and tiling effects