A heptagon has 7 corners.
7
Seven.
7
Faces = 8 Edges = 14 Corners = 8
A heptagon is a figure with 7 sides. Also, if by corner you mean edges, we can find that. There's the edges of the heptagonal base. So there's 7. Then we have the edges of where the lateral faces meet each other. There's another 7. You have 14 edges in a heptagonal pyramid. If, in fact, you meant "corners", then we add in the vertex (or apex) of the pyramid. Then you will have 15 "corners".
A cuboid or a pyramid with a heptagonal base are two possibilities.
Heptagonal is an adjective: the answer depends on the noun that it refers to. A heptagonal pyramid, a heptagonal dipyramid or a heptagonal prism or some other heptagonal shape?
there is 13 edges in a heptagonal pyramid.
A nonagon based pyramid. An octagon based dipyramid. An octagonal base with a double-apex "pyramid". A heptagonal base with a triple-apex "pyramid". A heptagonal pyramid with a double-apex "pyramid" on the other side. A pentagonal prism. There are many more.
An octahedron has 8 faces. there are a number of different configurations. A heptagonal pyramid has 14 edges and 8 corners. A hexagonal prism has 18 edges and 12 corners A quadrilateral based dipyramid (two quad based pyramids stuck together) has 12 edges and 6 corners. There are many other possible shapes.
Heptagonal is an adjective, not a noun! The answer will depend on whether you mean a heptagonal pyramid, a heptagonal bipyramid, a heptagonal prism or whatever.
a heptagonal pyramid has 8 faces
A heptagonal prism has two 7-sided bases.
A heptagonal what? Prism, pyramid or something else?