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Common Core Standard 6.G.1 , 6.G.3, 7.G.6

Convex Polygon

Concave Polygon

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Naming polygons game This could be a great way to review the polygon names. The polygon game shows a shape and then asks you questions about the name or number of sides.

Naming Polygons Tips and directions for naming polygons

When you draw a line through a Concave polygon it touches the concave polygon in more that two places,but with a Convex polygon the line only touches it in two places

Pre-Algebra/Expressions,Equations,Integers

Pre-Algebra/Fractions,Percents

Algebra/Exponents,Equations,Radicals

Concave polygons do have

internal angles greater than 180°

Convex polygons do not have any

internal angles greater than than 180°

1. Regular Polygons have equal length sides ( congruent sides)

2. Regular Polygons have equal length angles ( congruent angles)

3. Because the measure of each central angle is congruent in regular polygons, you can find the measure of the central angle by dividing the number of sides into 360◦

360 ÷ N (Number of sides) = Measure of the Central Angle of a regular polygon

Names of Polygons

regular polygon square triangle/properties and names of polygons

In this example the central angle equals

360/5 sides = 72 degrees

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Parallelograms

2D Polygons

Names of Polygon Shapes

Name	Number of Sides	Interior Angle Measure	Central Angle Measure 360/number of sides
Triangle	3	60°	120°
Quadrilateral	4	90°	90°
Pentagon	5	108°	72°
Hexagon	6	120°	60°
Heptagon or Septagon	7	128.5°	51.4°
Octagon	8	135°	45°
Nonagon or Enneagon	9	140°	40°
Decagon	10	144°	36°
Hendecagon or Undecagon	11	147.2°	32.72°
Dodecagon	12	150	30°
Triskaidecagon	13	152.3°	27.69°
Tetrakaidecagon	14	154.2°	25.71°
Pentadecagon	15	156°	24°
Hexakaidecagon	16	157.5°	22.5°
Heptadecagon	17	158.82°	21.17°
Octakaidecagon	18	160°	20°
Enneadecagon	19	161.05°	18.94°
Icosagon	20	162°	18°
Triacontagon	30	168°	12°
Tetracontagon	40	171°	9°
Pentacontagon	50	172.8°	7.2°
Hexacontagon	60	174°	6°
Heptacontagon	70	174.85°	5.14°
Octacontagon	80	175.5°	4.5°
Enneacontagon	90	176°	4°
Hectagon	100	176.4°	3.6°
Chiliagon	1000	176.64°	.36°
Myriagon	10,000	179.96°	.036°
n-gon	n	(n-2) × 180° / n
You can make names using Number of sides For example 40 Tetraconta	+1 henagon +2 digon +3 trigon +4 tetragon + 5 pentagon +6 hexagon +7 heptagon + 8 octagon +9 enneagon	Tetracontakaihenagon =41 sides Tetracontakaidigon =42 sides Tetracontakaitrigon = 43 sides

Rhombuses

Trapezoid properties

Central Angle

plus "Kai" for "and"

An easier and acceptable method of naming many sided polygons is as follows: 13 sided = 13-gon 17 sided =17-gon

Many of the shapes in Geometry are polygons. What is a polygon? A polygon is a two-dimensional shape that has straight lines. A polygon can have anywhere between three and an unlimited number of sides. All of the lines of a polygon connect which means there is not an opening. Each polygon is named according to it's the number of sides. Here are some examples of polygons.