Polygons - Definition, Examples, Quiz, FAQ, Trivia
Discover the wonderful world of polygons and how they shape our world!
What is a Polygon?
A polygon is a closed shape with straight sides. The word "polygon" comes from Greek words meaning "many angles." Polygons are all around us - in buildings, signs, and even in nature!
For a shape to be a polygon, it must have these features:
Straight Sides
All sides must be straight lines, not curved
Closed Shape
The shape must be completely closed with no openings
Two-Dimensional
Polygons are flat shapes, not 3D objects
Math Fact!
The simplest polygon is a triangle, which has 3 sides. A circle is not a polygon because it has curved sides.
Types of Polygons
Polygons are classified by how many sides they have. Each type has a special name based on the number of sides and angles:
Triangle
3 sides
Quadrilateral
4 sides
Hexagon
6 sides
Heptagon
7 sides
Octagon
8 sides
Nonagon
9 sides
There are many more polygon names for shapes with even more sides. For example, a 10-sided polygon is called a decagon, and a 12-sided polygon is called a dodecagon!
Regular & Irregular Polygons
Polygons can be either regular or irregular. This is an important way to classify shapes in geometry:
Regular Polygons
All sides are equal length and all angles are equal measure. Examples: square, equilateral triangle
Irregular Polygons
Sides are not all equal and angles are not all equal. Examples: rectangle, scalene triangle
Math Tip!
A rectangle is an irregular polygon because even though all angles are equal (90°), the sides are not all the same length!
Polygon Examples
Polygons aren't just math concepts - they're all around us in the real world! Here are some common examples:
Stop Signs
Octagons (8 sides) are used for stop signs so they're recognizable even from the back
Building Designs
Many buildings use rectangular and triangular shapes in their construction
Floor Tiles
Square and hexagonal tiles are common in home design
Nature
Honeycombs have hexagonal cells, and some crystals form triangular shapes
Next time you're outside, try to spot as many different polygons as you can. You might be surprised by how many you find!
Polygon Quiz
Test your polygon knowledge with this quiz! Answer all 5 questions to see how much you've learned.
Frequently Asked Questions
Here are answers to some common questions about polygons:
Math Trivia
Discover some amazing facts about polygons!
Ancient Discovery
Ancient Greek mathematicians studied polygons over 2,500 years ago. The word "polygon" comes from the Greek words "poly" (many) and "gonia" (angle).
Nature's Engineers
Honeybees use hexagons to build their honeycombs because this shape uses the least amount of wax to store the most honey - it's nature's most efficient design!
Strong Shapes
Triangles are the strongest polygon and are used in bridges and roofs because they distribute weight evenly. This is called structural integrity.
Soccer Ball Pattern
A traditional soccer ball is made of 12 pentagons and 20 hexagons. This shape is called a truncated icosahedron and it's almost perfectly round!
