22
15
6 faces, 12 edges
A 2D rectangle has no edges but has 4 boundaries, and a 3D rectangle is a rectangular prism and has 12 edges.
There are infinitely many shapes that do.
20
it has 20 edges.
An icosagon has no edges because it is a 20 sided polygon
A 3D icosagon is a three-dimensional geometric shape with 20 faces, each of which is a polygon with 20 edges and 20 vertices, forming a complex polyhedron. In a broader sense, it can be visualized as a 3D extension of a 2D icosagon, which is a polygon with 20 sides. The properties and measurements of a 3D icosagon can be analyzed using concepts from geometry and topology. However, it is worth noting that the term "3D icosagon" is not commonly used in mathematical literature.
a polygon with twenty one edges
6 edges.
A pentagonal prism will have 15 edges.
No corners and two edges !
I believe it would have nine edges.
12
15
Twelve.
8