By "corners", do you mean vertices or edges?
Twenty edges
20 edges, 11 vertices (corners) and 11 faces.
There are actually more than a pyramid that have that number of edges. Pentagonal star pyramid has 20 edges. Decagonal pyramid is another one.
Vertices: 20 Edges: 30 Faces: 12
It has 20 edges.
A decagonal based pyramid will have 11 faces, 11 vertices and 20 edges
A pyramid has one more corner and faces than the number of sides in its base; thus a decagonal pyramid has 10 + 1 = 11 faces and corners. A pyramid has twice as many edges as sides in its base; thus a decagonal pyramid has 2 X 10 = 20 edges.
By "corners", do you mean vertices or edges?
Twenty edges
20 edges, 11 vertices (corners) and 11 faces.
There are actually more than a pyramid that have that number of edges. Pentagonal star pyramid has 20 edges. Decagonal pyramid is another one.
There are 30 edges on a decagonal prism.
It depends on a decagonal what. A decagonal prism has 20 vertices. A decagonal pyramid has 11 vertices.
pentagonal antiprism, pentagonal deltohedron(not deltahedron), decagonal pyramid, and many more.
It depends on a decagonal what. There will be different answers for a decagonal pyramid, prism, dipyramid, etc.
30