Well, any shape with a triangular face.
I assume that you mean a shape that only has (identical) triangles for faces.
There are 2: the tetrahedron with 4 triangles, and the icosahedron with 20 triangles.
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What about a triangular dipyramid? Two triangular pyramids stuck together along one face?
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If you have one flat face and I have one curved face, which one of us is the 3d shape? Anyway, a 3d shape with pne f;at, circular face and one curved face could be: a section of a sphere or a section of an ellipsoid cut by a plane parallel to one of its axes, a section of a paraboloid or a cone. There are probably other shapes.
A cone.
A cylinder !
Hemisphere
sphere