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Number of diagonals = 18*(18-3)/2 = 135

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13y ago

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How many diagonals can be drawn from any vertex of a 20-sided polygon?

It is 18 diagonals


How many diagonals does an octadecagon have?

The formula for the number of diagonals (that is, lines joining non-adjacent vertices) belonging to any shape is n(n-3)/2. Therefore, an eighteen-sided polygon has 18 x (18 - 3)/2 = 135 diagonals.


How many sides does a 18 sided regular polygon have?

If you say this shape is 18 sided i would guess it has 18 sides. ;)


What is the special features of the dodecahedron?

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What is the name off an 18 sided shape?

All I can tell you is that a 16 sided shape is called a Hexadecagon


What are the names of shapes from 12 sided to 20?

Shapes with 12 to 20 sides are named as follows: a 12-sided shape is called a dodecagon, a 13-sided shape is a triskaidecagon, a 14-sided shape is a tetradecagon, a 15-sided shape is a pentadecagon, a 16-sided shape is a hexadecagon, a 17-sided shape is a heptadecagon, an 18-sided shape is an octadecagon, a 19-sided shape is a nonadecagon, and a 20-sided shape is an icosagon.


A 18 sided 2D shape?

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What is the name of an 18 sided shape?

octadecagon


What is an 18 sided shape?

enneadecagon or enneakaidecagon


What is the name of an 18 sided 3d shape?

no


18 sided 3d shape?

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How many diagonals can you draw in a polygon with 18 side?

153 diagonals.