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 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.
15
12
8
Twelve.
6 faces, 12 edges