Name that Polygon

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Name that Polygon!

• Sandy Hindy
• Teach the Teachers
• Collaborative 2000
• Thacher School

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You will know . . .

• . . . what a polygon is and
• . . . what a polygon is not and
• . . . that polygons are everywhere !

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What IS a Polygon?

• What IS it?

• What is it NOT?

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Is This a Polygon?
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Whats your vote?
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Yes or No?
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Well . . . ?
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Definition of a Polygon

• two-dimensional (flat) figure
• closed shape
• only one open space
• three or more straight sides
• three or more angles
• no crossed or extra lines

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Polygon Examples
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Congratulations!

• You know what polygons ARE
• You know what polygons ARE NOT
• You can see polygons everywhere!

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Now, you will know . . .
. . . how to classify polygons.
Here are some polygons and their names .
. .
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triangle (3 sides)
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square (4 sides)
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rectangle (4 sides)
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parallelogram (4 sides)
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rhombus (4 sides)
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trapezoid (4 sides)
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trapezoid (4 sides)
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Did you know . . . ?

• . . . that all 4 sided polygons have a special
  classification called QUADRILATERALS !

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Here are some more . . .
(notice that their words all end with -a-gon)
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pentagon (5 sides)
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hexagon (6 sides)
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heptagon (7 sides)
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octagon (8 sides)
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nonagon (9 sides)
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decagon (10 sides)
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hendecagon (11 sides)
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dodecagon (12 sides)
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Congratulations!

• You can now recognize these polygons

octagon 8
triangle 3
square
rectangle
pentagon 5
nonagon 9
parallelogram
rhombus
trapezoid
hexagon 6
decagon 10
quadrilaterals 4
heptagon 7
hendecagon 11
dodecagon 12
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Polygons can be . . .

• regular (equal sides and angles)

or

• irregular (not equal sides and angles)

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Also, polygons can be . . .

• convex (sticking out)

or

• concave (sticking in)