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What is a Polygon?. Dr. Beth McCulloch Vinson Athens State University PT3 Grant Funding, Summer 2000. A polygon is…. a many-sided figure a shape with three or more sides. What do we need to know about polygons?. How many sides does each polygon have? Do all polygons look the same?
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What is a Polygon? Dr. Beth McCulloch Vinson Athens State University PT3 Grant Funding, Summer 2000
A polygon is… a many-sided figure a shape with three or more sides.
What do we need to know about polygons? • How many sides does each polygon have? • Do all polygons look the same? • Can I know the name of a shape just by looking at it?
Triangle • A triangle has three sides. 1 3 2
Square • A square has four sides. 4 3 1 2
Pentagon • A pentagon has five sides. 1 5 2 4 3
Hexagon and Heptagon • A hexagon has six sides. (Hexagon and six both have an “x”.) • A heptagon has seven sides. heptagon hexagon
Octagon • An octagon has eight sides. Count the sides. If this octagon was red and had the word “Stop” written on it, then you would know where we see a lot of octagons.
Let’s Review: • The triangle is the smallest polygon. It only has three sides. • A pentagon has five sides. • A hexagon has six sides. • A heptagon has seven sides. • An octagon has eight sides.
Match these. Triangle eight sides Heptagon three sides Octagon seven sides
Match some more. Pentagon four sides Hexagon five sides Square six sides
Key Question: • A triangle is the smallest polygon because it has three sides. Can you have a two-sided polygon? Why or why not? Two lines don’t close to make a shape. They make an angle. 1 2
The END A Project Developed for Preparing Tomorrow’s Teachers to Use Technology (PT3) By Dr. Beth McCulloch Vinson Athens State University, School of Education http://www.athens.edu/vinsobm