A pyramid
A 5-sided 2-dimensional figure is a pentagon and a 5-sided 3-dimensional shape is a pentahedron.
Octahedron
In geometry a 29 sided shape is referred to as an icosikaidigon. The shape closely resembles an 3 dimensional octagon.
a polyhedron (if the shape is 3 dimensional) a polygon if it is a planar shape.
2 or 3 dimensional?
'Object' Do you mean 'shape' or 'solid'. a 2-dimensional shape is an hexagon a 3-dimensional solid is a hexahedron.
A 5-sided 2-dimensional figure is a pentagon and a 5-sided 3-dimensional shape is a pentahedron.
An octagon is an 8 sided 2 dimensional shape. A cylinder with the base of a hexagon (6 sided shape) would be an 8 sided 3 dimensional shape.
This question is faulty. Only 2-dimensional shapes can have their sides counted. For a 3-dimensional shape, you must count either edges or faces.
Triacontatetragon. Most mathematicians would call it a "34-gon."
Octahedron
A heptagon.
An 18 sided shape is called a octadecagon. This refers to both 2 dimensional and 3 dimensional shapes in a mathematical sense.
In geometry a 29 sided shape is referred to as an icosikaidigon. The shape closely resembles an 3 dimensional octagon.
a polyhedron (if the shape is 3 dimensional) a polygon if it is a planar shape.
2 or 3 dimensional?
NO!!! It is a seven(7) - sided 2-dimensional polygon. A Heptahedron is a seven(7) -sided 3-dimensional object.