How about a hemisphere ?
How about a cone or a pyramid
A hemisphere is one example.
Because the base of a cone is round, it is the only three dimensional figure with only one vertex.
pyramid or cone
How about a cone or maybe a pyramid
The only possible answer is a cone, because they don't have any other flate sufaces.
cone; circle is the base
# Square Pyramid # Rectangular Pyramid # Triangular Pyramid
A 3D shape with one base and three faces can only have triangular faces.
This figure is a CONE.
Such a figure is a pyramid.