A pyramid (3D)!
Some examples:
- triangular base pyramid
- square base pyramid
- rectangular base pyramid
- cone
sphere
A 3D shape with one base and three faces can only have triangular faces.
A sphere has no base, and since it has no base, it has only a surface area and no lateral area.
A cone.
It would help to know what shape you are talking about. But since you have not bothered to provide that information, I cannot provide a sensible answer.
A cone
A straight line.
In geometry, the only shape that has one surface is a plane.
cone
cone
A square based pyramid.
pentagonal pyramid