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A polygon is a plane shape with right sides.

You are watching: Names for polygons up to 20 sides

Is it a Polygon?

Polygons space 2-dimensional shapes. They space made of directly lines, and the form is "closed" (all the lines attach up).

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Polygon(straight sides)Not a Polygon(has a curve)Not a Polygon(open, no closed)

Types that Polygons

Regular or Irregular

A regular polygon has actually all angles equal and also all political parties equal, otherwise it is irregular

RegularIrregular

Concave or Convex

A convex polygon has actually no angles pointing inwards. Much more precisely, no internal angle deserve to be much more than 180°.

If any type of internal angle is greater than 180° climate the polygon is concave. (Think: concave has a "cave" in it)

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Convex Concave

Simple or Complex

A simple polygon has actually only one boundary, and it doesn"t cross end itself. A complex polygon intersects itself! countless rules around polygons don"t work when that is complex.

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Simple Polygon(this one"s a Pentagon)Complex Polygon(also a Pentagon)

More Examples

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Irregular HexagonConcave OctagonComplex Polygon(a "star polygon",in this instance a pentagram)

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Play with Them!

Try Interactive polygon ... Make them regular, concave or complex.

Names that Polygons


NameSidesShapeInterior Angle
If that is a continuous Polygon...
Triangle (or Trigon)3
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60°
Quadrilateral (or Tetragon)4
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90°
Pentagon5108°
Hexagon6
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120°
Heptagon (or Septagon)7
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128.571°
Octagon8
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135°
Nonagon (or Enneagon) 9
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140°
Decagon10
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144°
Hendecagon (or Undecagon)11
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147.273°
Dodecagon12
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150°
Triskaidecagon 13152.308°
Tetrakaidecagon 14154.286°
Pentadecagon15156°
Hexakaidecagon 16157.5°
Heptadecagon17158.824°
Octakaidecagon 18160°
Enneadecagon19161.053°
Icosagon20162°
Triacontagon30168°
Tetracontagon 40171°
Pentacontagon50172.8°
Hexacontagon 60174°
Heptacontagon 70174.857°
Octacontagon 80175.5°
Enneacontagon 90176°
Hectagon100176.4°
Chiliagon1,000179.64°
Myriagon10,000179.964°
Megagon1,000,000~180°
Googolgon10100~180°
n-gonn
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(n−2) × 180° / n

You can make names utilizing this method:


Sides
Start with...

20
Icosi...

30
Triaconta...

40
Tetraconta...

50
Pentaconta...

60
Hexaconta...

70
Heptaconta...

80
Octaconta...

90
Enneaconta...
100Hecta...
etc..

See more: Strengths And Weaknesses: North Advantages During The Civil War


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Sides
...end with
+1
...henagon
+2
...digon
+3
...trigon
+4
...tetragon
+5
...pentagon
+6
...hexagon
+7
...heptagon
+8
...octagon
+9
...enneagon

Example: a 62-sided polygon is a Hexacontadigon


BUT, because that polygons v 13 or more sides, it is ok (and easier) to write "13-gon", "14-gon" ... "100-gon", etc.


Remembering

Quadrilateral (4 Sides)

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A Quad Bike has 4 wheels

Pentagon (5 Sides)

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The "Pentagon" in Washington DC has 5 sides

Hexagon (6 Sides)

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Honeycomb has Hexagons

Septagon (7 Sides)

Think Septagon is a "Seven-agon"

Octagon(8 Sides)

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An Octopus has 8 tentacles

Nonagon (9 Sides)

Think Nonagon is a "Nine-agon"

Decagon (10 Sides)

Think Decagon has actually 10 sides,just choose our Decimal system has actually 10 digits


interactive Polygons internal Angles of polygons Exterior angles of polygon 2D shapes (simpler page)