A Decagon.
Dodecagon
it is a dodecagon
10 sided 2D shape is called a decagon 20 sided 2D shape is called a icosagon 30 sided 2D shape is a swimming pool 40 sided 2D shape is unknown 50 sided 2D shape is unknown 60 sided 2d shape is unknown 70 sided 2d shape is unknown 80 sided 2d shape is unknown 90 sided 2d shape is unknown 100 sided 2d shape is unknown 110 sided 2d shape is unknown 111 sided 2d shape is unknown 120 sided 2d shape is unknown 130 sided 2d shape is unknown
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It is a 12 sided dodecagon
It's a 2D shape.
A rhombus is a 2D shape.
2d
this is the shape of 2d cone
Dodecagon is the name for the regular 12 sided polygon, meaning that all its side lengths and angles are the same. Not sure if there is a name for a general 12 sided 2d shape.
A diamond is a 3D shape, specifically a type of polyhedron known as a rhombus. A rhombus is a quadrilateral with all sides of equal length, opposite sides parallel, and opposite angles equal. In a three-dimensional space, a diamond shape is a polyhedron with four faces that are congruent rhombi.