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A polygon is a aircraft shape with directly sides.

You are watching: Which polygon is a concave octagon?

Is that a Polygon?

Polygons room 2-dimensional shapes. They room made of directly lines, and also the shape is "closed" (all the lines affix up).

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

Types of Polygons

Regular or Irregular

A regular polygon has all angle equal and all political parties equal, otherwise it is irregular

RegularIrregular

Concave or Convex

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

If any kind of internal edge is better 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 over itself. A complex polygon intersects itself! many rules around polygons don"t work-related when the 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 polygons ... Make them regular, concave or complex.

Names that Polygons


NameSidesShapeInterior Angle
If the 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 deserve to make names making use of 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: 1998 Ford Expedition Vacuum Hose Diagram For Vacuum Hoses On 1990


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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, the is yes sir (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 actually Hexagons

Septagon (7 Sides)

Think Septagon is a "Seven-agon"

Octagon(8 Sides)

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An Octopus has actually 8 tentacles

Nonagon (9 Sides)

Think Nonagon is a "Nine-agon"

Decagon (10 Sides)

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


interactive Polygons inner Angles of polygons Exterior angle of polygons 2D shapes (simpler page)