Answer:
Explanation:
The specifications of a decagonal pyramid would be the following
It has one face that is a decagon.
35 diagonals in the base.
10 isosceles triangles as faces above the base
11 vertices - 10 in the base and 1 at the top
20 edges - 10 in the base and 10 above the base
This can all be seen in the picture of the decagonal pyramid below. The only decagonal face is on the base of the pyramid as the top is a vertice where all of the triangles meet.