That's called a Decagon.
12 faces, 30 edges and 20 vertices. It has 2 decagons plus 10 rectangles between them giving 12 faces It has 2 x 10 vertices on each decagon giving 20 vertices It has 10 edges round each decagon plus another 10 joining the vertices of one decagon to the other decagon's vertices giving 2x10+10 = 30 vertices
In 2-d, the naming of polygons is such that a 10 sided shape is a decagon. Even if it is a 5-pointed star shape, it is a decagon. A concave decagon (rather than convex) but still a decagon. In 3-d, a decahedron, possibly, with the term "sides" being used for "faces".
Not sure what a decagonal is. Since the question refers to faces, edges and vertices, it may be assumed that the object in question is 3-dimensional. A decagon certainly is not, so decagonal cannot be a mistaken name for a decagon.
Decagon
10 faces 10 faces
a decagon
A decagon is a polygon with 10 sides and 1 surface face
A decagon is a 10 sided polygon that has 10 vertices and 1 flat face
1 face 10 edges
That's called a Decagon.
Assuming a regular decagon is the base of the prism, it would be 10 faces. With an irregular decagon, it is possible that two (or more) of the edges of the decagons are perpendicular, so all 12 faces could have perpendicular edges.
10 A decagon is a plane (2-d) figure and so it has only one face. It has 10 sides and 10 vertices.
12 faces, 30 edges and 20 vertices. It has 2 decagons plus 10 rectangles between them giving 12 faces It has 2 x 10 vertices on each decagon giving 20 vertices It has 10 edges round each decagon plus another 10 joining the vertices of one decagon to the other decagon's vertices giving 2x10+10 = 30 vertices
In 2-d, the naming of polygons is such that a 10 sided shape is a decagon. Even if it is a 5-pointed star shape, it is a decagon. A concave decagon (rather than convex) but still a decagon. In 3-d, a decahedron, possibly, with the term "sides" being used for "faces".
deca = ten so you have the ten top faces and then the base or 10 + 1 = 11
Not sure what a decagonal is. Since the question refers to faces, edges and vertices, it may be assumed that the object in question is 3-dimensional. A decagon certainly is not, so decagonal cannot be a mistaken name for a decagon.